JP2016006457A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the toner residual amount of a container.SOLUTION: An image formation apparatus comprises a container which accommodates toner supplied to a developing part, an ultrasonic sensor part which is arranged in the container, transmits an ultrasonic wave and receives a reflection wave of the ultrasonic wave, and a control part which controls the operation of the ultrasonic sensor part. The ultrasonic sensor part transmits the ultrasonic waves in plural directions. The control part measures time from transmission of the ultrasonic wave to reception of the reflection wave for each of the ultrasonic waves transmitted in the plural directions, obtains the toner deposition height at each reflection position of the ultrasonic waves transmitted in the plural directions on the basis of the measured time, and obtains the toner residual amount of the container on the basis of the toner deposition height at each reflection position.

Description

  The present invention relates to an image forming apparatus to which a container for storing toner is attached.

  2. Description of the Related Art Conventionally, there is known an image forming apparatus that develops an electrostatic latent image formed based on image data into a toner image, transfers the toner image to a sheet, and outputs it. Such an image forming apparatus includes a developing unit that develops the electrostatic latent image into a toner image.

  Although toner is accommodated in the developing unit, the toner is reduced by execution of printing, so it is necessary to supply toner to the developing unit. Therefore, normally, a container for storing toner for replenishment is attached to the image forming apparatus. This container can be attached to and detached from the image forming apparatus. When an already mounted container becomes empty, the empty container can be replaced with a new container.

  In such an image forming apparatus in which toner is supplied from the container to the developing unit, the remaining amount of toner in the container is detected in order to notify the user of the replacement timing of the container. For example, in Patent Document 1, an ultrasonic sensor for detecting the remaining amount of toner in a container is disposed in the container.

  When detecting the toner remaining amount in the container using the ultrasonic sensor, the control unit that controls the operation of the ultrasonic sensor first transmits an ultrasonic wave from the ultrasonic sensor. Thereby, the ultrasonic wave is reflected by the toner, and the reflected wave of the reflected ultrasonic wave is received by the ultrasonic sensor. When the reflected wave is received by the ultrasonic sensor, the control unit obtains the ultrasonic wave propagation time that is the time from the transmission of the ultrasonic wave to the reception of the reflected wave, and the ultrasonic wave is reflected based on the ultrasonic wave propagation time. The toner accumulation height at the reflected position is obtained. Then, the control unit obtains the toner remaining amount in the container based on the toner accumulation height.

JP 2006-350072 A

  Here, depending on the shape of the container, as the toner consumption of the container progresses, the toner accumulation height in the container varies depending on the location. For example, in the region near the lower corner in the container, the toner is difficult to move because the toner contacts a pair of side walls forming the corner. For this reason, in the region near the corner in the container, the toner tends to remain (the toner accumulation height tends to be large) compared to other regions (for example, the region near the replenishing port from which the toner is discharged). Note that the area where the toner is likely to remain varies depending on the shape of the toner.

  However, in Patent Document 1, an ultrasonic wave is transmitted only in one direction from the position where the ultrasonic sensor is installed, and the ultrasonic wave is reflected based on the propagation time of the ultrasonic wave (the time from the transmission of the ultrasonic wave to the reception of the reflected wave). The toner accumulation height at the position is obtained, and the remaining amount of toner in the container is obtained based on the toner accumulation height. That is, the remaining amount of toner in the container is obtained based on the toner accumulation height at one location in the container. For this reason, Patent Document 1 has a disadvantage that the detection accuracy of the toner remaining amount in the container is low.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of accurately detecting the remaining amount of toner in a container.

  In order to achieve the above object, an image forming apparatus of the present invention includes a developing unit that develops an electrostatic latent image into a toner image, a container that contains toner to be replenished to the developing unit, an ultrasonic wave disposed in the container, And an ultrasonic sensor unit that receives the reflected wave of the ultrasonic wave reflected by the toner or the inner surface of the container, and a control unit that controls the operation of the ultrasonic sensor unit. The ultrasonic sensor unit transmits ultrasonic waves in a plurality of predetermined directions in the container. The control unit measures the time from the transmission of the ultrasonic wave to the reception of the reflected wave for each of the ultrasonic waves transmitted in a plurality of directions based on the output of the ultrasonic sensor unit, and the plurality of directions based on the measured time. The toner accumulation height at each reflection position of the ultrasonic wave transmitted to is obtained, and the toner remaining amount in the container is obtained based on the toner accumulation height at each reflection position.

  In the configuration of the present invention, for each of the ultrasonic waves transmitted in a plurality of directions, the time from the transmission of the ultrasonic waves to the reception of the reflected wave is measured, and the ultrasonic waves transmitted in a plurality of directions are measured based on the measured times. The toner accumulation height at each reflection position is obtained, and the toner remaining amount in the container is obtained based on the toner accumulation height at each reflection position, and the obtained toner remaining amount reflects the toner accumulation heights at a plurality of locations in the container. It becomes the value. Thereby, even if the toner accumulation height in the container varies depending on the location, the remaining amount of toner in the container can be accurately detected.

  As described above, according to the present invention, the remaining amount of toner in the container can be detected with high accuracy.

1 is a schematic diagram of a multifunction machine according to an embodiment of the present invention. 1 is a block diagram showing a hardware configuration of a multifunction machine according to an embodiment of the present invention. The top view which showed the inside of the container with which the MFP by one Embodiment of this invention is mounted | worn (The figure which showed the transmission direction of the ultrasonic wave) Sectional drawing which showed the inside of the container with which the multifunctional device by one Embodiment of this invention is mounted | worn (The figure which showed the transmission direction of the ultrasonic wave) Schematic diagram of the ultrasonic sensor unit installed in the container shown in FIG. FIG. 4 is a cross-sectional view showing a state where toner is contained in the container shown in FIG. The flowchart figure which showed the flow of the toner remaining amount detection performed in the multifunctional device by one Embodiment of this invention.

  An embodiment of the present invention will be described by taking as an example a multi-function peripheral equipped with a plurality of functions such as a printer function and a copy function.

<Overall configuration of MFP>
As illustrated in FIG. 1, the multifunction peripheral 100 (corresponding to an “image forming apparatus”) includes an image reading unit 1 and a printing unit 2. The image reading unit 1 reads a document and generates image data. The printing unit 2 transports the paper P along the paper transport path 101 and forms a toner image based on the image data. Then, the printing unit 2 prints the toner image on the paper P being conveyed, and discharges the printed paper P to the discharge tray 102.

  The printing unit 2 includes a paper feeding unit 3, a paper transport unit 4, an image forming unit 5, and a fixing unit 6. The paper feed unit 3 includes a pickup roller 31 and a paper feed roller pair 32, and supplies the paper P stored in the paper cassette 33 to the paper transport path 101. The paper transport unit 4 includes a plurality of transport roller pairs 41 and transports the paper P along the paper transport path 101.

  The image forming unit 5 includes a photosensitive drum 51, a charging device 52, an exposure device 53, a developing device 54 (corresponding to a “developing unit”), a transfer roller 55, and a cleaning device 56.

  At the time of image formation, the photosensitive drum 51 rotates, and the charging device 52 charges the surface of the photosensitive drum 51. The exposure device 53 exposes the surface of the photosensitive drum 51 and forms an electrostatic latent image on the surface of the photosensitive drum 51. The developing device 54 supplies toner to the electrostatic latent image formed on the surface of the photosensitive drum 51, and develops the electrostatic latent image into a toner image.

  The transfer roller 55 is in pressure contact with the surface of the photoconductive drum 51 and forms a transfer nip with the photoconductive drum 51. As the paper P enters the transfer nip, the toner image on the surface of the photosensitive drum 51 is transferred to the paper P. The cleaning device 56 removes toner remaining on the surface of the photosensitive drum 51.

  The fixing unit 6 includes a heating roller 61 and a pressure roller 62. The heating roller 61 has a built-in heat source. The pressure roller 62 is in pressure contact with the heating roller 61 and forms a fixing nip with the heating roller 61. The paper P on which the toner image is transferred is heated and pressurized by passing through the fixing nip. As a result, the toner image is fixed on the paper P and printing is completed.

  Here, toner is accommodated in the developing device 54, but since the toner is consumed by execution of printing, it is necessary to supply toner to the developing device 54. For this reason, the multi-function device 100 is equipped with a container 20 that stores toner for supply. When the remaining amount of toner in the developing device 54 falls below a predetermined amount, toner supply from the container 20 to the developing device 54 is performed.

  The container 20 is detachable from the apparatus main body. For example, a part of the apparatus cover is an opening / closing cover (not shown), and when the opening / closing cover is opened, a space for mounting the container 20 is exposed. When the toner in the already installed container 20 runs out, the user replaces the empty container 20 with a new container 20.

  The multifunction device 100 also includes an operation panel 7. The operation panel 7 includes a liquid crystal display panel 71 with a touch panel. The liquid crystal display panel 71 displays soft keys and messages for accepting various settings. Alternatively, the liquid crystal display panel 71 displays information indicating the device state. For example, the liquid crystal display panel 71 displays information (indicator or the like) indicating the toner remaining amount in the container 20. The operation panel 7 is provided with hard keys 72 such as a start key and a numeric keypad.

<Hardware configuration of MFP>
As shown in FIG. 2, the multifunction peripheral 100 includes a main control unit 110 (corresponding to a “control unit”). The main control unit 110 includes a CPU 111, an image processing unit 112, and a storage unit 113. The image processing unit 112 includes an ASIC dedicated to image processing, and performs image processing (enlargement / reduction, density conversion, data format conversion, etc.) on the image data. The storage unit 113 includes a ROM and a RAM, and stores a control program and data. The main control unit 110 controls the operation of the multifunction peripheral 100 based on the program and data stored in the storage unit 113.

  Specifically, the main control unit 110 is connected to the image reading unit 1 and the printing unit 2 (the paper feeding unit 3, the paper transport unit 4, the image forming unit 5, and the fixing unit 6), and controls the reading operation and the printing operation. To do. The main control unit 110 is connected to the operation panel 7 and controls the display operation of the operation panel 7 or detects an operation performed on the operation panel 7. For example, the main control unit 110 detects the remaining amount of toner in the container 20 (details will be described later). Then, the main control unit 110 causes the operation panel 7 to display information indicating the remaining amount of toner in the container 20.

<Container configuration>
As shown in FIGS. 3 and 4, the container 20 is formed in a box shape whose longitudinal direction is the front-rear direction of the apparatus. The container 20 stores toner for replenishment therein (portion surrounded by the top surface portion, the bottom portion, and the side wall portion).

  A conveying screw 21 for conveying the toner in the container 20 is provided below the container 20. The conveying screw 21 integrally has spiral fins that are spirally formed at a constant pitch in the rotation axis direction, and is arranged so that the rotation axis extends along the front-rear direction. The conveying screw 21 conveys the toner in the container 20 forward by rotating.

  Further, a supply port 22 for supplying toner in the container 20 to the developing device 54 is formed at the bottom of the container 20. The replenishing port 22 is disposed on one end side in the front-rear direction of the conveying screw 21 (the front side in the container 20) and is connected to the developing device 54. As a result, the toner in the container 20 is transported to the supply port 22 by the rotation of the transport screw 21 and discharged from the supply port 22. The toner discharged from the supply port 22 is supplied to the developing device 54.

  An ultrasonic sensor unit 23 for detecting the remaining amount of toner in the container 20 is disposed above the container 20. As shown in FIG. 5, the ultrasonic sensor unit 23 includes a transmission unit 24a and a reception unit 24b. The transmitter 24a transmits ultrasonic waves. The receiving unit 24 b receives the reflected ultrasonic wave reflected from the toner or the inner surface of the container 20.

  Here, the ultrasonic sensor unit 23 includes a plurality of transmitters 24a and a plurality of receivers 24b respectively corresponding to the plurality of transmitters 24a. For example, the plurality of transmission units 24 a and the plurality of reception units 24 b are unitized and installed in the container 20. The plurality of transmitters 24a transmit ultrasonic waves in different directions. Each of the plurality of receiving units 24b receives reflected ultrasonic waves transmitted from the corresponding transmitting unit 24a among the plurality of transmitting units 24a. That is, the ultrasonic sensor unit 23 transmits ultrasonic waves in a plurality of different directions and receives reflected waves from a plurality of different directions. 3 to 5, the traveling direction of the ultrasonic wave is indicated by a dotted arrow.

  For example, the ultrasonic sensor unit 23 is disposed at a substantially central portion of the toner storage area in which the toner in the container 20 is stored in a plan view. Of the plurality of sets each including the transmitting unit 24a and the receiving unit 24b, one set transmits an ultrasonic wave directly below and receives a reflected wave of the ultrasonic wave. The remaining sets transmit ultrasonic waves toward the corners present on the lower side (bottom side) of the toner containing area and receive the reflected waves of the ultrasonic waves. As an example, there are four corners on the lower side of the toner storage area, and the directions toward the four corners are the transmission directions of ultrasonic waves. In this case, a total of five sets of transmitter 24a and receiver 24b are installed. Alternatively, each direction toward the two corners on the diagonal line among the four corners on the lower side of the toner storage area may be set as the ultrasonic wave transmission direction. In this case, a total of three sets of transmitter 24a and receiver 24b are installed.

  In addition, the number of transmission units 24a and reception units 24b is not particularly limited, and the transmission direction of ultrasonic waves is not particularly limited. Further, a plurality of sets each including the transmission unit 24a and the reception unit 24b may be individually installed in the container 20 without being unitized.

  The ultrasonic sensor unit 23 is connected to the main control unit 110 as shown in FIG. Then, the main control unit 110 controls the operation of the ultrasonic sensor unit 23 and detects the remaining amount of toner in the container 20 based on the output of the ultrasonic sensor unit 23 (details will be described later).

  When transmitting ultrasonic waves to the ultrasonic sensor unit 23, the main control unit 110 transmits an ultrasonic transmission request signal for requesting transmission of ultrasonic waves to the transmission unit 24a. Thereby, the transmission part 24a transmits an ultrasonic wave.

  The receiving unit 24b includes, for example, an amplifier circuit, a sample hold circuit, a comparator circuit, and the like. When the receiving unit 24b receives the reflected wave, the amplifier circuit amplifies the voltage generated by the reception of the reflected wave. The sample hold circuit samples and holds the peak value of the output signal from the amplifier circuit. The comparator circuit compares the hold value of the sample hold circuit with a threshold value. When the hold value exceeds the threshold value, the receiving unit 24b outputs a signal of a predetermined level (hereinafter referred to as an ultrasonic reception signal) to the main control unit 110.

<Detection of remaining toner in container>
As shown in FIG. 6, as the toner in the container 20 is consumed, the remaining amount of toner in the container 20 gradually decreases. At this time, the method of reducing the toner in the container 20 varies depending on the location, and the toner accumulation height does not decrease uniformly over the entire area in the container 20. That is, as the consumption of toner in the container 20 progresses, the toner accumulation height in the container 20 varies depending on the location.

  Accordingly, when the main controller 110 detects the remaining amount of toner in the container 20, the main controller 110 transmits ultrasonic waves to the plurality of transmitters 24a (transmits ultrasonic waves in a plurality of directions from the ultrasonic sensor 23). Thereby, the ultrasonic waves transmitted in a plurality of directions are reflected at different positions, and the reflected waves are received by the corresponding receiving units 24b. Then, the main control unit 110 detects the remaining amount of toner in the container 20 based on the outputs of the plurality of receiving units 24b that have received the reflected waves.

  Hereinafter, the flow of detecting the remaining amount of toner in the container 20 will be described with reference to FIG. The start of the flowchart of FIG. 7 is, for example, after the toner supply from the container 20 to the developing device 54 is completed (after the rotation of the conveying screw 21 is stopped). However, the timing for detecting the remaining amount of toner in the container 20 is not particularly limited, and may be performed when the multifunction peripheral 100 is activated (including when returning from sleep) or when a user instruction is received. Also good. Alternatively, the toner remaining amount detection of the container 20 may be performed at a predetermined time interval.

  In step S <b> 1, the main control unit 110 transmits an ultrasonic transmission request signal to the ultrasonic sensor unit 23. The ultrasonic sensor unit 23 that has received the ultrasonic transmission request signal transmits ultrasonic waves in a plurality of directions. That is, the plurality of transmitters 24a transmit ultrasonic waves in different directions. At this time, the plurality of transmitters 24a transmit ultrasonic waves in a predetermined order, not simultaneously. Thereby, the ultrasonic waves transmitted in a plurality of directions are respectively reflected by the toner. And the some receiving part 24b receives the reflected wave of the ultrasonic wave each transmitted from the corresponding transmission part 24a among the some transmission parts 24a.

  In step S <b> 2, the main control unit 110 measures the ultrasonic propagation time, which is the time from the transmission of the ultrasonic wave to the reception of the reflected wave, for each of the ultrasonic waves transmitted from the ultrasonic sensor unit 23 in a plurality of directions. . Specifically, the main control unit 110 measures the time from the transmission of the ultrasonic transmission request signal to the reception of the ultrasonic reception signal as the ultrasonic propagation time.

  In step S3, the main control unit 110 obtains the toner accumulation height at each reflection position of the ultrasonic waves transmitted in a plurality of directions based on the ultrasonic propagation times of the ultrasonic waves transmitted in a plurality of directions. For example, toner accumulation height information (table data) in which the correspondence between the ultrasonic wave propagation time and the toner accumulation height is predetermined for each transmission direction of ultrasonic waves is stored in the storage unit 113. Then, the main control unit 110 discriminates the toner accumulation height corresponding to each ultrasonic wave propagation time of ultrasonic waves transmitted in a plurality of directions based on the toner accumulation height information, so that the toner accumulation at each reflection position is determined. Find the height. Note that the correspondence relationship between the ultrasonic propagation time and the toner accumulation height specified in the toner accumulation height information can be obtained experimentally.

  Alternatively, the distance from the installation position of the ultrasonic sensor unit 23 to the reflection position is calculated based on the ultrasonic propagation time and the ultrasonic velocity, and the reflection position is calculated based on the calculated distance (for example, using a trigonometric function). The toner accumulation height may be obtained.

  In step S4, the main controller 110 obtains the average height of the toner accumulation height at each reflection position. When ultrasonic waves are transmitted in the directions shown in FIGS. 3 and 4, for example, the toner accumulation height obtained by averaging the toner accumulation heights at the four corners of the toner containing area is obtained, and the average toner accumulation height is obtained. And the average value of the toner accumulation height at the center of the toner containing area is obtained as the average height. Thereafter, in step S5, the main control unit 110 obtains the total remaining toner amount in the container 20 based on the average height.

  For example, the storage unit 113 stores toner remaining amount information (table data and the like). This toner remaining amount information is information in which the toner remaining amount corresponding to the average height is determined in advance. For example, when determining the toner remaining amount information, the toner in the container 20 is decreased by a predetermined amount, and the average height is obtained each time the predetermined amount is decreased, and the average height range corresponding to the toner remaining amount at that time is determined. . Then, the main control unit 110 determines the remaining toner amount corresponding to the average height based on the remaining toner information, and obtains the determined remaining toner amount as the total remaining toner amount in the container 20.

  Note that the main control unit 110 causes the storage unit 113 to store the detection result of the remaining amount of toner in the container 20. Then, the main control unit 110 determines the remaining amount of toner to be displayed on the operation panel 7 if the remaining amount of toner detected at the previous detection of the remaining amount of toner is different from the remaining amount of toner detected at the current remaining amount of toner. Update.

  As described above, the multifunction peripheral 100 (image forming apparatus) of the present embodiment includes a developing device 54 (developing unit) that develops an electrostatic latent image into a toner image, and a container that stores toner supplied to the developing device 54. 20, an ultrasonic sensor unit 23 that is disposed in the container 20, transmits an ultrasonic wave, and receives a reflected wave of the ultrasonic wave reflected from the toner or the inner surface of the container 20, and controls the operation of the ultrasonic sensor unit 23. A main control unit 110 (control unit). The ultrasonic sensor unit 23 transmits ultrasonic waves in a plurality of predetermined directions in the container 20. Based on the output of the ultrasonic sensor unit 23, the main control unit 110 measures the time from the transmission of the ultrasonic wave to the reception of the reflected wave for each of the ultrasonic waves transmitted in a plurality of directions. Based on this, the toner accumulation height at each reflection position of ultrasonic waves transmitted in a plurality of directions is obtained, and the remaining amount of toner in the container 20 is obtained based on the toner accumulation height at each reflection position.

  In the configuration of this embodiment, for each of the ultrasonic waves transmitted in a plurality of directions, the time from the transmission of the ultrasonic waves to the reception of the reflected wave is measured, and the ultrasonic waves transmitted in a plurality of directions based on the measured times. The toner accumulation height at each reflection position is obtained, and the toner remaining amount in the container 20 is obtained based on the toner accumulation height at each reflection position. This is a value that reflects this. Thereby, even if the toner accumulation height in the container 20 varies depending on the location, the remaining amount of toner in the container 20 can be accurately detected.

  In the present embodiment, as described above, the main control unit 110 obtains the average height of the toner accumulation height at each reflection position of the ultrasonic waves transmitted in a plurality of directions, and the container is based on the average height. A toner remaining amount of 20 is obtained. With this configuration, it is possible to easily obtain the remaining amount of toner reflecting the toner accumulation height at a plurality of locations in the container 20.

  In the present embodiment, as described above, the information indicating the remaining amount of toner corresponding to the average height (the average value of the toner accumulation height at each reflection position of the ultrasonic waves transmitted in a plurality of directions) is determined in advance. The remaining toner amount information is stored in the storage unit 113. Then, the main control unit 110 determines the toner remaining amount corresponding to the average height based on the toner remaining amount information, and obtains the determined toner remaining amount as the toner remaining amount of the container 20. If the toner remaining amount information is determined in advance, the toner remaining amount in the container 20 can be easily obtained by obtaining the toner accumulation height and the average height of each reflection position of ultrasonic waves transmitted in a plurality of directions. Can be requested.

  In the present embodiment, as described above, the ultrasonic sensor unit 23 includes a plurality of transmission units 24a and a plurality of reception units 24b respectively corresponding to the plurality of transmission units 24a. And the some transmission part 24a transmits an ultrasonic wave in a mutually different direction. In addition, each of the plurality of receiving units 24b receives reflected ultrasonic waves transmitted from the corresponding transmitting unit 24a among the plurality of transmitting units 24a. With this configuration, it is possible to easily transmit ultrasonic waves in a plurality of directions within the container 20. That is, it is possible to easily obtain the toner accumulation height at a plurality of locations in the container 20.

  In the present embodiment, as described above, the predetermined transmitter 24 a among the plurality of transmitters 24 a transmits the ultrasonic wave toward the corner in the container 20. With this configuration, it is possible to obtain the remaining amount of toner reflecting the toner accumulation height at the corner in the container 20.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above-described embodiment but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

20 Container 23 Ultrasonic Sensor 24a Transmitter 24b Receiver 54 Developer (Developer)
110 Main control unit (control unit)
113 storage unit

Claims (5)

A developing unit for developing the electrostatic latent image into a toner image;
A container for storing toner to be replenished to the developing unit;
An ultrasonic sensor unit that is disposed in the container, transmits ultrasonic waves, and receives reflected waves of ultrasonic waves reflected from the inner surface of the toner or the container;
A control unit for controlling the operation of the ultrasonic sensor unit,
The ultrasonic sensor unit transmits ultrasonic waves in a plurality of predetermined directions in the container,
The control unit measures the time from the transmission of the ultrasonic wave to the reception of the reflected wave for each of the ultrasonic waves transmitted in the plurality of directions based on the output of the ultrasonic sensor unit, and based on the measured time An image forming apparatus, comprising: obtaining a toner accumulation height at each reflection position of ultrasonic waves transmitted in the plurality of directions; and obtaining a toner remaining amount of the container based on the toner accumulation height at each reflection position.   The image forming apparatus according to claim 1, wherein the control unit obtains an average height of toner accumulation heights at the respective reflection positions, and obtains a toner remaining amount in the container based on the average height. A storage unit that stores toner remaining amount information that is information that predetermines the remaining amount of toner corresponding to the average height;
3. The control unit according to claim 2, wherein the control unit determines a toner remaining amount corresponding to the average height based on the toner remaining amount information, and recognizes the determined toner remaining amount as a toner remaining amount of the container. The image forming apparatus described. The ultrasonic sensor unit includes a plurality of transmitters and a plurality of receivers corresponding to the plurality of transmitters,
The plurality of transmitters transmit ultrasonic waves in different directions,
The plurality of receiving units each receive a reflected wave of an ultrasonic wave transmitted from a corresponding transmitting unit among the plurality of transmitting units. Image forming apparatus.   The image forming apparatus according to claim 4, wherein a predetermined transmitter of the plurality of transmitters transmits an ultrasonic wave toward a corner in the container.

Images