JP3548550B2 - Image forming device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus including a light emitting element that emits light as a sheet presence / absence detection unit in a sheet transport path and a light receiving element that receives reflected light of light output from the light emitting element.
[0002]
[Prior art]
In a conventional image forming apparatus, a photo interrupter, which is a mechanical detection method, is used as a paper detection unit of a paper conveyance path. The photo interrupter has a movable plate between the light emitting element and the light receiving element in the photo coupler, and when the recording paper is not detected, light from the light emitting element side can reach the light receiving element side without being interrupted. A constant voltage is output.
[0003]
On the other hand, when the recording paper is being detected, the recording paper hits the movable plate and the plate moves, and the light output from the light emitting side is blocked before reaching the light receiving side, so the output is not output. Absent. The presence or absence of recording paper can be determined based on the presence or absence of both output voltages. However, immediately after the recording paper has passed, the plate tends to return to the original position by a force of a spring or the like. At this time, since the plate returns to its original position while vibrating due to the recoil of the spring, the output level vibrates near the presence / absence level of the paper, and it takes time from the presence of the paper to the normal detection of the absence of the paper. is there.
[0004]
In order to feed the paper at high speed and accurately, it is necessary to keep the paper interval constant, and for that purpose, the leading and trailing edges of the recording paper must be determined. If there is chattering due to the mechanical vibration of the photo interrupter, the trailing edge of the recording paper cannot be accurately detected.
[0005]
In order to prevent this and detect the presence / absence of paper at high speed, a reflection type optical detection sensor has been used. The reflection-type optical detection sensor is a detection means that does not contact the recording paper and uses high-speed detection because it uses the fact that the output differs due to the difference in the reflection intensity between the recording paper and a plate made of a material with high reflectance. Means.
[0006]
However, the reflective optical detection sensor has a drawback that the output value fluctuates. It is conceivable that the output changes due to the deterioration of the light emitting element and the light receiving element due to the durability, and the deterioration of the reflectance of the reflector due to the paper dust during paper feeding. As a countermeasure for this, conventionally, means for adjusting the amount of light emitted from the reflection type optical detection sensor when the main power supply of the apparatus is turned on to keep the output voltage constant has been used.
[0007]
[Problems to be solved by the invention]
In the method of adjusting the characteristic deterioration during operation of the reflection type optical detection sensor only when the main power is turned on, in a high-speed machine with a large number of printed sheets, the adjustment interval may be too wide and may be insufficient. . In other words, between the time when the main power is turned on and the time when the power is turned off and when the next power is turned on, a large amount of printing is performed, particularly in a high-speed image forming apparatus, so that paper dust generated during paper conveyance is reduced. , And accumulate on the light emitting element or the light receiving element of the reflection type optical detection sensor. As a result, the accuracy of paper detection may be reduced, which may cause erroneous jam detection.
[0008]
Also, if a method of performing adjustment before and after the job is adopted, if the number of sheets to be printed in one job is very large, similarly, paper dust generated during paper conveyance is reflected. It accumulates on the light emitting element or light receiving element of the optical detection sensor. As a result, the accuracy of paper detection may be reduced, which may cause erroneous jam detection.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an optical apparatus including a paper storage unit that stores paper, a transport member that transports the paper, a transport path, and a light emitting element and a light receiving element that detect the presence or absence of paper in the transport path. And a driver for changing a light emission amount of at least one optical sensor disposed in the conveyance path, wherein a sheet replenishment detecting a replenishment operation of the paper stored in the paper storage unit is provided. It is an object of the present invention to provide an image forming apparatus which has a detecting means and adjusts a light emission amount of the optical sensor according to an output of the paper supply detecting means.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
[0011]
FIG. 1 shows an internal structure of a main body of an image forming apparatus to which the present invention is applied. In this image forming apparatus, a plurality of (34, 35, 36, 37) paper feed units having a reflective optical detection mechanism capable of adjusting the amount of emitted light are arranged as means for determining the presence or absence of a sheet. A paper feeder 15 having a capacity is mounted.
[0012]
As shown in FIG. 1, the image forming apparatus of the present embodiment includes a main body image output unit 10 for outputting a manuscript image on a recording sheet, a main body image input unit 11 for reading manuscript image data, and a main body image input unit 11. An automatic document feeder 12 is provided at the upper part.
[0013]
In the main body image input unit 11, light is emitted from a light source 21 that scans in the left-right direction in FIG. 1 onto a document placed on a document table on the top of the input unit. The light is reflected by the original, and an optical image is formed on the CCD 26 through the mirrors 22, 23, 24 and the lens 25. In the CCD 26, the formed image is converted into an electric signal to be digital image data. The image data is subjected to image conversion according to a user's request and stored in an image memory (not shown).
[0014]
When outputting an image, the image data stored in the image memory is called out in the main body image output unit 10, the digital data is converted back into an analog signal, and the optical irradiation unit 27 converts the image data into a laser beam optical signal. The light is irradiated onto the photosensitive drum 31 via the mirror 30 and scans the photosensitive drum 31. As a result, an electrostatic latent image corresponding to the document image is formed on the photosensitive drum 31. Next, the developing device 33 places toner on the electrostatic latent image, transfers the toner onto the recording paper conveyed inside the main body, and further fixes the toner on the recording paper by the fixing roller 32. Thereafter, the recording paper is discharged out of the main body image output unit 10, and post-processing such as stapling and bookbinding is performed by the post-processing device 13 in accordance with a user's request.
[0015]
Next, the recording paper feeding system will be described. FIG. 2 is an enlarged view of the paper feed units 36 and 37 of FIG. The paper feed unit 36 includes a paper feed roller 204, a paper feed clutch 207, a pull-out roller 205, a pull-out clutch 206, a pickup solenoid 208, a pickup roller 209, which are a paper feed member, and a paper feed path 221, a reflective optical paper. A paper feed unit 201 including detection sensors 202 and 203 is mounted. The paper feed unit 37 is also provided with a paper feed unit 211 similar to the paper feed unit 201 in the paper feed unit 36.
[0016]
When feeding paper, first, the pickup solenoid 208 is turned off, the pickup roller 209 is lowered, and the pickup roller 209 is pressed against the recording paper 210. Then, the pickup roller 209 is rotated to start sheet feeding.
[0017]
Then, the paper feed motor is turned on, and the paper feed clutch 207 transmits the power of the paper feed motor to the paper feed roller 204 according to a paper feed timing signal sent from the controller. At this time, the recording paper 210 is fed one by one due to the difference in frictional force between the paper feed roller 204 and the second paper, and the reflection type optical paper detection sensor 202 is turned off from on to detect the presence of paper. I do. Further, the paper is transported to the paper transport path 221 toward the pull-out roller 205.
[0018]
The pickup solenoid 208 is turned on at a certain time after the reflection type optical paper detection sensor 202 is turned off, and raises the pickup roller 209 so that the second and subsequent sheets are not fed. The paper feed clutch 207 is turned off at a certain timing according to the detection signals of the reflection type optical paper detection sensor 202 and the sensor reflection type optical paper detection 203. A reflection type optical paper detection sensor 203 is provided at the end of the reflection type optical paper detection sensor 202 via a paper feed roller 204. By detecting the presence or absence of a sheet with both sensors 202 and 203, continuous feeding is performed. It is used as a means for detecting paper jam and at the same time as detecting paper jam.
[0019]
When the first sheet feeding operation is completed, the pickup solenoid 208 is turned off, and the pickup roller 209 is lowered again to prepare for feeding of the next sheet. When feeding the second and subsequent sheets, the sheet feeding clutch 207 is turned on again and the same operation is performed.
[0020]
Reference numerals 230 and 232 in the drawing denote paper presence / absence detection sensors for detecting the remaining amount and presence / absence of paper in the paper cassettes 240 and 250, respectively, which are paper storage units. Prompts the operator to replenish paper.
[0021]
The image forming apparatus of the present embodiment has an automatic cassette change function that is a function of automatically switching to another paper cassette having paper of the same size when the paper cassette currently in use runs out of paper. As described above, if there is no paper in the cassette currently in use and the automatic cassette change function is set, and the same size paper exists in another paper cassette, the automatic cassette change function is used. Then, paper supply from another paper cassette is started immediately, and print output is continued.
[0022]
The paper cassettes 240 and 250, which are paper storage units, are front-loading paper cassettes, which can be pulled out independently of the paper feed units 201 and 211, respectively.
[0023]
Reference numerals 231 and 233 denote cassette open / close detection sensors for detecting the opening / closing of the paper cassette. When the sensor is off, the cassette is pulled out. When the sensor is on, the cassette is normally mounted and closed. It is in the state that it was.
[0024]
FIG. 3 is a sectional configuration diagram of a reflection type optical sensor using a prism as a reflection plate used in the present embodiment. (A) is a configuration diagram when there is no paper, and (B) is a configuration diagram when there is paper. The same applies when the reflector is a mirror. A light emitting element 302 and a light receiving element 303 are mounted on the sensor substrate 301, and the light emitting element 302 and the light receiving element 303 are covered with a cover 304.
[0025]
As described above, the light emitting element and the light receiving element are arranged in the paper transport direction, adjacent to each other, and closely arranged. When the paper is transported, the surface area in contact with the paper is larger than that of a sensor in which the light emitting element and the light receiving element are arranged to face each other. Paper powder easily accumulates on the upper surface of the optical sensor that comes into contact with the paper.
[0026]
A mirror or a prism 305 is provided so as to face the sensor substrate 301, and light emitted from the light emitting element 302 is reflected by the prism 305 when there is no paper in (A), and reflected light is detected by the light receiving element 303.
[0027]
On the other hand, when there is a sheet shown in (B), the light from the light emitting element 302 is blocked by the recording sheet 306, and the reflectance of the recording sheet 306 is lower than that of the prism 305. The presence or absence of the recording paper can be determined from the difference.
[0028]
However, when a current flows through the light emitting element 302 or the light receiving element 303, the amount of light emission or the light receiving sensitivity may be reduced depending on the amount of current or time. Therefore, it is necessary to periodically adjust the current of the light emitting element and keep the output of the light receiving element 303 constant. In addition, since the output differs depending on the mechanical inclination at the time of attachment and the individual difference in the sensitivity of the light emitting element 302 and the light receiving element 303, this adjustment must be performed in each reflection optical sensor.
[0029]
FIG. 4 is a block diagram of a control system related to paper feeding and conveyance of the image forming apparatus according to the embodiment of the present invention. The CPU 401 controls the operation of the clutch and the pickup solenoid 510 inside the paper feeding unit 201, the operation of the paper feeding motor 509 outside the paper feeding unit 201, and the dimming of the reflection type optical paper detection sensor 202 and the sensor 203. ing. When dimming the reflection type optical paper detection sensor 202 and the reflection type optical paper detection sensor 203, dimming is performed by the driver circuit 404, and when driving the paper feed motor 509, clutch, solenoid, etc. 510, the motor and clutch driving circuit are used. Driving is performed via 503.
[0030]
The paper presence / absence detection sensors 230 and 232 detect the presence / absence of paper in the paper cassette, respectively, and the cassette open / close detection sensors 231 and 233 detect the open / close of the paper cassette, respectively.
[0031]
When the paper presence / absence detection sensors 230 and 232 detect that the paper has run out during the printing operation, the operator is prompted to perform a paper supply operation. Further, when the paper is replenished and the cassette opening / closing detection sensors 231 and 233 detect that the paper cassette is normally mounted, the reflection type optical paper detection sensors 202, 203, 212 and 213 are dimmed and the light receiving level is set in advance. The output setting digital value Dom is set.
[0032]
FIG. 5 is a diagram showing the sensor driver circuit 404 shown in FIG. 4 in detail.
[0033]
An 8-bit or 16-bit digital output value Dout corresponding to the light emission intensity of the LED 302 as a light emitting element is output from the CPU 401. The digital output value Dout is converted into an analog input voltage Vin by the D / A converter 402, and a constant current for driving the LED 302, which is a light emitting element, is output by the operational amplifier 407 to drive the LED 302 at a constant current. When the photodiode 303 serving as a light receiving element receives the reflected light from the prism 305, a current almost proportional to the received light intensity flows.
[0034]
The operational amplifier 408 amplifies the output voltage Vout in order to keep the current flowing through the photodiode 303 constant. As a result, a large change in output can be obtained even when the change in received light intensity is small. The output of the operational amplifier 408 is branched to an A / D converter 403 and a comparator 406. The comparator 406 compares the output voltage of the operational amplifier 408 with a reference voltage, and the output voltage has two values of a high level and a low level. . This binary output is used by the CPU 401 to determine whether there is a sheet or no sheet.
[0035]
On the other hand, the voltage input to the A / D converter 403 at the output of the operational amplifier 408 is converted from an analog value to an 8-bit or 16-bit digital input value Din by the A / D converter 403 and input to the CPU 401. In the light control sequence shown in FIG. 6, the CPU 401 adjusts the output digital value Dout so that the digital input value Din is set to a light control level stored in advance.
[0036]
That is, the digital output value Dout is increased when the light path from the light emitting element to the light receiving element is blocked by the life or paper dust and the light receiving intensity is reduced. Conversely, when the received light intensity becomes higher than the previous time, such as after cleaning of paper dust or the like, the output digital value Dout is reduced. By repeatedly performing this control until a predetermined level is reached, the output voltage of the reflection type optical paper detection sensor is kept constant, and a stable output can be obtained.
[0037]
FIG. 9 is a graph of the input voltage Vout from the A / D converter 403 to the CPU 401 and the output voltage Vin from the CPU 401 to the D / A converter 402 for the reflection type optical paper detection sensor. Where Vi _max Is the maximum voltage that can be output by the circuit shown in FIG. _h Is a threshold value for detecting the presence or absence of recording paper by the reflection type optical paper detection sensor, Vo _M Is a preset output set voltage value of the reflection type optical paper detection sensor. When the device is shipped, the output voltage is Vo _M At point A0 equal to, the input voltage is Via1. In (A), it is assumed that the apparatus has been used by a user and the state has been reduced to A1 due to the influence of the life, paper dust, and the like. At this time, if the light emission amount is adjusted, the CPU 401 shown in FIG. 5 increases the input value by the predetermined input value Δ. The value of Δ may be a constant value or a value calculated in consideration of the decrease in output from A0 to A1. However, if Δ is set to a small value, the adjustment takes a long time. Therefore, it is desired that the value be an appropriate value in consideration of the adjustment time and accuracy.
[0038]
When the input is increased by Δ to Via2, the output becomes Voa2. _M Since> Voa2, the input voltage is increased again by Δ. This is repeated until the output voltage becomes Vo _M If it is (A4), the adjustment is completed and the input voltage is set to Via4. On the other hand, as shown in FIG. _max Anyway, Vo _M In the case of> Vob6, the sensor considers that the attenuation due to paper dust or the life has been completed, and notifies the user of cleaning or replacement of the sensor.
[0039]
FIG. 6 is a flowchart showing a dimming operation by the CPU 401 of the reflection type optical paper detection sensor when the image forming apparatus performs a paper supply operation during a printing operation. The control program according to this flowchart is written in the built-in memory of the CPU 401.
[0040]
When the user starts copying from the operation unit or the like (S1), first, the presence or absence of sheets in the sheet cassette specified by the user or specified by the automatic cassette change is detected (S2). If there is a sheet, a sheet feeding operation such as rotating the sheet feeding motor 509 is started (S3). As described with reference to FIG. 2, at this time, the optical sensor 202 detects the conveyed sheet and turns from on to off, and then also turns off the optical sensor 203 (S4). Then, a printing operation is performed (S5), and it is determined whether or not the copy job is completed (S9). If completed, the copy in S10 is completed. If the copy job has not been completed, the process returns to step S2 to perform a copy operation on the next recording sheet.
[0041]
If it is determined in S2 that there is no paper, the paper feeding operation is stopped and the operator is urged to replenish the paper (S6). Here, if there is paper of the same size in another paper cassette, the automatic cassette change function is used. Feeding of paper from another paper cassette is started, and the printing operation is continued. In other words, the flow of FIG. 6 has been started in another cassette.
[0042]
Then, the apparatus waits for the sheet supply operation to be performed by the operator, the sheet cassette is pulled out, the sheets are supplied to the sheet cassette, and the sheet cassette is normally mounted. The transition from the absence of paper to the presence of paper is detected by the paper presence / absence detection sensors such as 230 and 232, and the transition from the state where the paper cassette is pulled out to the state where the paper cassette is normally mounted is detected by the open / close detection sensors such as 231 and 233. When it is detected, it is considered that the paper supply is completed (S7) At the timing when the paper supply is completed, the light control sequence is started and the light emission amount of the sensor 202 or the sensor 203 as the reflection type optical paper detection mechanism is adjusted. (S8).
[0043]
Here, the timing of the start of light control is not limited to the above-described embodiment, but may be, for example, a time when only the transition from the absence of paper to the presence of paper in the paper cassette is detected. In this case, even if the light is dimmed even though there is no paper in the paper cassette, there is no meaning in the dimming without the paper. Therefore, real-time dimming at a timing at which the paper can be fed is desirable.
[0044]
In addition, regardless of whether or not the paper cassette is replenished with paper, only the transition from the state where the paper cassette is pulled out to the state where the paper cassette is normally mounted may be detected by the open / close detection sensors such as 231 and 233. In this case, dimming is performed even when paper is replenished in a state where there is still paper in the paper cassette. Dimmable.
[0045]
Further, the light control may be started immediately after the cassette is pulled out, regardless of whether or not the paper cassette is replenished with paper. In this case, in particular, in most cases, the dimming has already been completed before the cassette is mounted, so that there is an advantage that printing can be started immediately after the cassette is mounted.
[0046]
FIG. 7 is a flowchart illustrating in detail the dimming sequence by the CPU 401 in S8. In this dimming sequence, in the case of dimming a plurality of sensors belonging to the same unit, when a command to start dimming is issued, the first sensor is selected (S21), and the sensor removes paper. It is checked whether or not it has been detected (S22). If the paper is detected, the dimming cannot be performed, and the process proceeds to the dimming of the next sensor (S27).
[0047]
When the paper is not detected, the digital input value Din of the AD converter 403, which is the current light reception amount, is measured (S23), and the digital input value Din and the output setting digital value Dom corresponding to the output setting voltage value Vom are measured. A comparison is made (S24). If the digital input value Din is different from the output setting digital value Dom, it is determined whether the digital output value Dout corresponding to the current LED current output from the DA converter 402 is the maximum value corresponding to the settable Vimax. (S25) If it is the maximum value, an NG display is displayed to inform the user that the sensor cannot be adjusted, and the process proceeds to S27.
[0048]
If the digital output value Dout is not the maximum value that can be set, a value obtained by adding a constant value Δ to the current digital output value Dout is output (S28), and the digital input value Din on the light receiving side is measured again (S23). . This control is repeated until the received light amount digital input value Din becomes equal to or more than the output set digital value Dom. When the digital input value Din becomes equal to or more than the output set digital value Dom, the digital output value Dout is set as the light emission output of the sensor, and then the light control It is checked whether there is a sensor to be performed (S27). If there is a sensor, the sensor is selected (S29), and the same light control is performed. When the dimming of all the sensors is completed, the dimming sequence ends (S30).
[0049]
FIG. 8 is a diagram illustrating an example of a sensor that should be dimmed when replenishing a sheet cassette with sheets. With reference to the drawing of FIG. 2, a method of determining a sensor to be dimmed in FIG. 8 will be specifically described.
[0050]
(Example 1)
When paper is replenished to the paper cassette 250 of the paper feed stage 37 while the paper cassette 240 of the paper feed stage 36 shown in FIG. ... Since the sensors 202 and 203 are used for continuous paper feeding, dimming cannot be performed.
[0051]
(Example 2)
When the paper supply in the paper supply stage 36 in FIG. 2 is stopped and the paper cassette 250 in the paper supply stage 37 is replenished with paper, and the paper cassette is normally mounted... In this case, since there is a large loss of time after the cassette is mounted, the dimming of the sensors 203, 212, and 213 used by the mounted paper cassette for feeding is performed.
[0052]
(Example 3)
When the paper cassette 250 of the paper feed stage 37 in FIG. 2 is in a state where the job is being executed and the continuous paper feeding is being performed, and the paper cassette 240 of the paper feed stage 36 is replenished with paper and the paper cassette is normally mounted. ... Since the sensors 203, 212, and 213 are used for continuous paper feeding, dimming cannot be performed, so the sensor 203 is dimmed.
[0053]
(Example 4)
When the paper supply in the paper supply stage 37 in FIG. 2 is stopped and the paper cassette 240 in the paper supply stage 36 is replenished with paper, and the paper cassette is normally mounted... In this case, since there is much time loss after the cassette is mounted, the dimming of the sensors 202 and 203 used by the mounted paper cassette for feeding is performed.
[0054]
In the above-described embodiment, the dimming of a sensor used when paper is replenished in the paper cassette and the paper is fed, or a sensor particularly requiring dimming among them, is performed. Further, even when the paper is being continuously fed from another paper source, the paper is replenished, and among the sensors used when the paper is fed, as long as dimming is necessary, The dimming of the sensor is performed. This enables stable paper transport without erroneous detection of paper jam.Furthermore, even when the auto cassette change function is operating or continuous paper is being fed from another paper cassette, the dimming is not possible. Therefore, it is possible to avoid stopping the copy job in the middle, and as a result, downtime is reduced.
[0055]
Also, the embodiment of FIG. 8 is not limited to this, and the optical sensor that requires dimming varies depending on, for example, the configuration of the paper feed stage and the arrangement of the optical sensor.
[0056]
In the image forming apparatus of this embodiment, the dimming sequence shown in FIG. 7 is performed when the main power of the image forming apparatus is turned on or before and after each copy job. At this time, since the process is performed for all the reflective optical detection mechanisms disposed in the image forming apparatus, the number of times the copy job is stopped halfway can be reduced, and stable paper conveyance can be performed even during large-scale copying. . Note that the optical sensor according to the embodiment of the present invention is only the one disposed in the sheet feeding unit, but is not limited to this. For example, an optical sensor may be provided at the paper discharge unit, finisher, or both-side path.
[0057]
【The invention's effect】
As described above in detail, the present invention adjusts the light emission amount of the optical sensor based on the detection of the paper supply operation of the paper cassette included in the paper supply unit. The light amount of the light emitting element of the sensor is adjusted, and an image forming apparatus having an optical sensor without erroneous detection of a jam due to the influence of paper dust or the like can be provided, and the paper can always be stably transported.
[Brief description of the drawings]
FIG. 1 is an overall schematic diagram of an image forming apparatus using a reflection type optical paper detection sensor.
FIG. 2 is an enlarged view of a paper feeding unit of the image forming apparatus of FIG. 1 using a reflection type optical paper detection sensor.
FIG. 3 is an internal configuration diagram of a light emitting element, a light receiving element, and the like of the reflection type optical paper detection sensor.
FIG. 4 is a block diagram of a control system related to sheet feeding and conveyance of a sheet of the image forming apparatus.
FIG. 5 is a sensor drive circuit of the reflection type optical paper detection sensor.
FIG. 6 is a flowchart relating to a dimming operation.
FIG. 7 is a flowchart of a light control sequence.
FIG. 8 is a diagram illustrating an example of a sensor to be adjusted for light when a sheet cassette is supplied with sheets.
FIG. 9 is a diagram showing an input / output characteristic curve at the time of adjustment of the reflection type optical paper detection sensor.
[Explanation of symbols]
10 Main unit image output unit
11 Body image input section
12 Automatic Document Feeder
14 Post-processing equipment
15 Large capacity paper feeder
21 Light source
22,23,24,30 mirror
25, 29 lenses
26 CCD
27 Optical irradiation unit
28 Scanner
31 Photosensitive drum
32 fixing roller
33 Developer
34, 35, 36, 37 paper feed stage
201, 211 Paper feed unit
202, 203, 212, 213 Reflective optical paper detection sensor
204, 214 paper feed roller
205,215 Pull-out roller
206,216 Pull-out clutch
207,217 Paper feed clutch
208,218 Pickup solenoid
209, 219 Pickup roller
210, 220 Recording paper
230,232 Sensor for detecting paper presence in paper cassette
231,233 Open / close detection sensor for paper cassette
240,250 paper cassette
301 Sensor board
302 Light emitting device (LED)
303 Light receiving element (photodiode)
304 cover
305 prism
306 Recording paper
401 CPU
402 D / A converter
403 A / D converter
404 Sensor driver circuit
406 comparator
407,408 Operational amplifier
504 ROM
505 RAM
508 Motor clutch drive circuit
509 Paper feed motor
510 Clutch solenoid

Claims (7)

A paper storage unit for storing paper, a transport member for transporting the paper, a transport path, an optical sensor having a light emitting element and a light receiving element for detecting the presence or absence of paper in the transport path, and at least one disposed in the transport path. An image forming apparatus comprising: a driver for changing a light emission amount of one optical sensor; and a sheet replenishing operation detecting means for detecting a replenishing operation of the sheet stored in the sheet storing part, wherein the sheet replenishing operation detection is performed. An image forming apparatus that adjusts a light emission amount of the optical sensor according to an output of the unit. 2. The image forming apparatus according to claim 1, wherein in the optical sensor, the light emitting element and the light receiving element are arranged adjacent to each other, and a reflection mechanism is provided on the opposite surface. 3. The image according to claim 1, wherein a plurality of the paper storage units are provided, and the light emission amount of an optical sensor corresponding to the paper supply unit that has detected the paper supply is adjusted by the paper supply operation detection unit. Forming equipment. A plurality of the paper storage units are provided, and while the paper is supplied from one of the paper storage units, the light emission amount of the optical sensor corresponding to the paper being supplied to the other paper storage unit by the paper supply operation detecting unit is adjusted. The image forming apparatus according to claim 1, wherein The image forming apparatus according to claim 1, wherein the sheet supply operation detecting unit detects a transition from a state of no paper in the paper storage unit to a state of having paper. 2. The image forming apparatus according to claim 1, wherein the sheet supply operation detecting unit detects a state where the sheet storage unit is pulled out. The image forming apparatus according to claim 1, wherein the sheet supply operation detection unit detects a transition from a state where the sheet storage unit is pulled out to a state where the sheet storage unit is attached.

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