JP2018171878A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device which enables users to easily check consumption information regarding a consumption agent housing part for housing a consumption agent.SOLUTION: A process cartridge 3 storing a toner which is consumed as images are formed is provided so as to be attached to/detached from a housing 2. A non-volatile display 33 is attached to the process cartridge 3 and consumption information regarding the process cartridge 3 is displayed in the non-volatile display 33. Users can visually check the non-volatile display 33 attached to the process cartridge 3 through an observation hole 23 provided on an upper surface 15 of the housing 2 from the outside of the housing 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus such as a printer.

  2. Description of the Related Art Conventionally, an image forming apparatus generally has a configuration in which a consumable item (consumable agent storage unit) such as a toner cartridge that stores toner or an ink cartridge that stores ink is detachably mounted in a housing.

  In the image forming apparatus having this configuration, it is proposed that a non-volatile display such as electronic paper is attached to the consumable, and information such as the type of consumable, product code, and unit price is displayed on the non-volatile display ( For example, see Patent Document 1). Thereby, similar consumables can be distinguished from the display of the non-volatile display.

JP 2010-99933 A

  However, when the information displayed on the non-volatile display is confirmed after the consumable is mounted in the housing, it is necessary to access the housing in which the consumable is arranged, which is troublesome. . That is, an opening for attaching and detaching consumables is formed in the housing, and a cover for opening and closing the opening is provided. When checking the display information on the non-volatile display of consumables installed in the housing, open the cover and take out the consumables from the housing once, or look inside the housing from the opening, and The display must be visually confirmed, and the confirmation work is troublesome.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of easily confirming consumption information relating to a consumable agent storage unit that stores a consumable agent.

  In order to achieve the above object, an image forming apparatus according to an aspect of the present invention is an image forming apparatus that forms an image on a sheet, and is attached to the housing and the housing in a detachable manner. A consumable agent storage unit that stores a consumable agent that is consumed along with the formation of an image; and a display that is attached to the consumable agent storage unit and displays consumption information about the consumable agent storage unit. The display can be viewed from the outside.

  According to this configuration, the consumable agent storage unit that stores the consumable agent that is consumed along with image formation is provided to be detachable from the housing. A display is attached to the consumable agent storage unit, and consumption information regarding the consumable agent storage unit is displayed on the display. And the display with which the housing | casing was attached to the consumable agent accommodating part is comprised so that visual recognition is possible from the outside. Therefore, the display can be visually recognized without performing an access operation such as opening and closing of a cover provided in the housing, so that the wear information displayed on the display can be easily confirmed from the outside of the housing.

  According to the present invention, it is possible to easily check the consumption information displayed on the display attached to the consumable agent container from the outside of the housing.

1 is a perspective view of a printer according to an embodiment of the present invention, showing a state in which a process cartridge is mounted on a housing and a front cover is closed. FIG. 3 is a perspective view of the printer, showing a state where the front cover is opened and the process cartridge is detached from the housing. It is a perspective view of a process cartridge. It is a figure which shows the example of a screen of a non-volatile display. It is sectional drawing when a printer is cut | disconnected by the cut surface perpendicular | vertical to a viewing window. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. It is a circuit diagram of the connection circuit which connects an IC chip and a graphic chip. FIG. 3 is a perspective view of a printer having a configuration in which a viewing window is provided on the front cover, showing a state in which the process cartridge is mounted on the housing and the front cover is closed. FIG. 4 is a perspective view of a printer having a configuration in which a viewing window is provided on the front cover, showing a state in which the front cover is opened and the process cartridge is detached from the housing. It is sectional drawing when a printer is cut | disconnected by the cut surface perpendicular | vertical to a viewing window. It is a perspective view of a printer for explaining a modification of a shape of a projection part, and shows a state where a front cover is opened and a process cartridge is detached from a casing. FIG. 4 is a perspective view of a printer having a configuration in which a toner box is detachably attached to a notch provided in a housing, and shows a state in which the toner box is attached to the notch. FIG. 4 is a perspective view of a printer having a configuration in which a toner box is detachably attached to a notch provided in a housing, and shows a state in which the toner box is detached from the notch.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Appearance configuration of printer>
A printer 1 (an example of an image forming apparatus) shown in FIGS. 1 and 2 is a monochrome laser printer.

  The printer 1 includes a housing 2 and a process cartridge 3 (an example of a consumable agent storage unit and a storage box) that is detachably attached to the housing 2.

  The housing 2 has a first side surface 11 and a second side surface 12 that are parallel to each other.

  In addition, in order to use in the following description, the direction orthogonal to the first side surface 11 is referred to as “front-rear direction”, and the first side surface 11 side in the front-rear direction is referred to as “front side”. Further, the left and right are defined based on the state of the printer 1 viewed from the front side.

  The first side surface 11 is provided with an opening 13 and a front cover 14 that opens and closes the opening 13. The front cover 14 has a closed position (a position shown in FIG. 1) that closes the opening 13 around an axis extending in the left-right direction, and an open position (the figure shown in FIG. 1) that falls from the closed position to the front side and opens the opening 13. 2 (position shown in FIG. 2).

  The housing 2 has an upper surface 15 that extends over the upper ends of the first side surface 11 and the second side surface 12. A recess 16 that is recessed downward is formed on the upper surface 15, and a region in the recess 16 and on the first side surface 11 side of the recess 16 is formed as a paper discharge tray 21.

  A paper feed tray 22 is detachably provided at the bottom of the housing 2. In other words, the paper feed tray 22 is mounted on the bottom of the housing 2 so that it can be pulled out from the mounting position to the front side. The paper feed tray 22 is configured to be supported in a state where a plurality of sheets such as printing paper are stacked.

  The process cartridge 3 is detachably mounted at a cartridge mounting position in the housing 2. In a state where the front cover 14 is opened, the process cartridge 3 can be mounted at the cartridge mounting position through the opening 13, and the process cartridge 3 can be detached from the cartridge mounting position.

  As shown in FIGS. 2 and 3, the process cartridge 3 includes a photosensitive drum 31 (an example of a photosensitive member), a developing housing 32, and the like. The developing case 32 may be formed integrally with a frame that supports the photosensitive drum 31, or may be configured to be coupled to and separated from the frame. In the latter configuration, the developing case 32 may be detachable from the frame through the opening 13 with the frame remaining in the case 2, in which case the developing case 32 is It is an example of a storage box.

  The developing case 32 contains toner (developer). Further, the developing case 32 is provided with a developing roller (not shown), and the toner accommodated in the developing case 32 is supplied to the peripheral surface of the photosensitive drum 31 by the developing roller.

  Printing on the sheet is performed in a state where the process cartridge 3 is mounted at the cartridge mounting position and the front cover 14 is closed. At the time of printing, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 31, and the toner contained in the developing housing 32 is supplied to the peripheral surface of the photosensitive drum 31 by the developing roller. As a result, the electrostatic latent image is developed into a toner image. On the other hand, a sheet is sent out from the sheet feeding tray 22 and conveyed in the housing 2 toward the sheet discharge tray 21. In the middle of the conveyance, the toner image carried on the photosensitive drum 31 is transferred to the sheet and fixed, whereby printing on the sheet is achieved.

  A non-volatile display 33 is provided on the upper surface of the developing case 32. The non-volatile display 33 is a display such as electronic paper that can maintain image display without receiving power supply. The display area of the non-volatile display 33 has a rectangular outer shape extending in the left-right direction.

  As shown in FIG. 4, the non-volatile display 33 displays the remaining amount of toner stored in the developing housing 32 (process cartridge 3). The remaining amount of toner is, for example, a percentage in which the full amount of toner accommodated in the developing case 32 is 100%, and the remaining amount of toner is displayed as a numerical value on the nonvolatile display 33, for example.

  The non-volatile display 33 may display not only the remaining amount of toner but also other information related to the process cartridge 3, for example, information such as the product number of the process cartridge 3 and the durable number of the photosensitive drums 31. As shown in FIG. 4, information such as an error that has occurred in the printer 1 may be displayed.

  As shown in FIG. 3, a lock recess 35 that is recessed to the right side is formed on the left side surface of the developing case 32. Correspondingly, a lock member 36 is provided in the housing 2 on the left side of the cartridge mounting position. The lock member 36 is displaceable to a lock position that is advanced to the right side from a wall surface 37 that extends in the front-rear direction and the vertical direction on the left side of the cartridge mounting position, and a lock release position that is retracted to the left side from the lock position.

  When the lock member 36 is advanced to the lock position and the lock member 36 is engaged with the lock recess 35 with the process cartridge 3 mounted at the cartridge mounting position, the process cartridge 3 is prohibited from being detached from the cartridge mounting position ( Cartridge lock). When the lock member 36 is retracted from the lock position to the lock release position and the engagement between the lock recess 35 and the lock member 36 is released, the removal of the process cartridge 3 from the cartridge mounting position is permitted.

  Further, on the upper surface 15 of the housing 2, a viewing window 23 that vertically penetrates the upper surface 15 is formed at a position facing the nonvolatile display 33 of the process cartridge 3 mounted at the cartridge mounting position in the vertical direction. ing. The size of the viewing window 23 is larger than the size of the non-volatile display 33. When the viewing window 23 and the non-volatile display 33 are projected onto a plane from the up and down direction, the projection of the non-volatile display 33 is projected within the projection of the viewing window 23. It will fit. Therefore, the user can visually recognize the non-volatile display 33 through the viewing window 23 without opening the front cover 14.

  A transparent member 24 made of a transparent material is fitted into the viewing window 23, and the viewing window 23 is closed by the transparent member 24 so that the inside of the housing 2 can be seen from the outside.

  As shown in FIG. 5, a cylindrical projecting portion 25 that projects downward from the entire circumference of the periphery of the viewing window 23 is provided in the housing 2. An elastic member 26 made of an elastic material such as sponge or rubber is attached to the lower end of the protruding portion 25 over the entire circumference. The protrusion 25 and the elastic member 26 are colored in an opaque color.

  In a state where the process cartridge 3 is mounted at the cartridge mounting position, the elastic member 26 elastically contacts the peripheral edge of the nonvolatile display 33. Thus, the protrusion 25 and the elastic member 26 are colored in an opaque color, and the elastic member 26 elastically contacts the peripheral edge of the non-volatile display 33, so that the protrusion 25 and the elastic member 26 are The protrusion 25 and the elastic member 26 can function as a light shielding member and prevent the outside light that enters the housing 2 from the observation window 23 from spreading inside the housing 2. For this reason, it is possible to suppress external light from entering the photosensitive drum 31, and it is possible to suppress deterioration in print quality and deterioration of the photosensitive drum 31 due to the incident external light.

<Electrical configuration of printer>
As illustrated in FIG. 6, the printer 1 includes an ASIC (Application Specific Integrated Circuit) 41, a ROM 42, and a RAM 43.

  The ASIC 41 includes a CPU 44 (an example of a control unit). The CPU 44 controls each unit by executing a program stored in the ROM 42 based on a signal input to the ASIC 41 and the like. When the control (program) is executed by the CPU 44, the RAM 43 is used as a work area. The RAM 43 may include a nonvolatile memory such as NVRAM (Non Volatile RAM).

  In addition to the ROM 42 and the RAM 43, a solenoid 45 is connected to the ASIC 41. The solenoid 45 is a drive source that displaces the lock member 36 between the lock position and the lock release position.

  Further, an IC chip 51 is connected to the ASIC 41. On the other hand, the process cartridge 3 (developing housing 32) is provided with a graphic chip 52 for controlling the display of the nonvolatile display 33. The IC chip 51 and the graphic chip 52 are communicably connected, whereby the CPU 44 can control the display of the nonvolatile display 33 via the IC chip 51 and the graphic chip 52.

<Connection circuit>
In a state where the process cartridge 3 is mounted at the cartridge mounting position in the housing 2, as shown in FIG. 7, a connection circuit 61 is provided between the IC chip 51 and the graphic chip 52 so that they can communicate with each other. Composed. The connection circuit 61 is divided into a main body side circuit 62 provided on the housing 2 and a cartridge side circuit 63 provided on the process cartridge 3 side.

  The IC chip 51 includes a Vcc pin 71, an IN / OUT pin 72, a GND pin 73, and an IN pin 74. Corresponding to this, the main body side circuit 62 includes four terminals 75, 76, 77 and 78. The Vcc pin 71 and the terminal 75 are connected by the first wiring 81, the IN / OUT pin 72 and the terminal 76 are connected by the second wiring 82, and the GND pin 73 and the terminal 77 are connected by the third wiring 83, The IN pin 74 and the terminal 78 are connected by a fourth wiring 84. The second wiring 82 and the third wiring 83 are connected via the first resistor 85.

  The graphic chip 52 has a Vcc pin 91, an IN pin 92, a GND pin 93, and an OUT pin 94. Correspondingly, the cartridge side circuit 63 includes four terminals 95, 96, 97, 98. The Vcc pin 91 and the terminal 95 are connected by the fifth wiring 101, the IN pin 92 and the terminal 96 are connected by the sixth wiring 102, the GND pin 93 and the terminal 97 are connected by the seventh wiring 103, and the OUT pin 94 and the terminal 98 are connected by an eighth wiring 104. The fifth wiring 101 and the sixth wiring 102 are connected via the second resistor 105.

  For example, as shown in FIG. 2, the terminals 95 to 98 of the cartridge side circuit 63 are arranged in a line in the front-rear direction on the right side surface of the developing housing 32. On the other hand, in the housing 2, the terminals 75 to 78 of the main body side circuit 62 are arranged in a form corresponding to the arrangement form of the terminals 95 to 98 of the cartridge side circuit 63, that is, arranged in a line in the front-rear direction. The terminals 75 to 78 of the main body side circuit 62 are elastically biased toward the left side.

  When the process cartridge 3 is not mounted at the cartridge mounting position and the main body side circuit 62 and the cartridge side circuit 63 are not connected, the terminal 75 of the main body side circuit 62 is open. The / OUT pin 72 is electrically connected to the GND pin 73 through the first resistor 85. Therefore, when the IN / OUT pin 72 is set to the signal input mode, the potential of the GND pin 73, that is, the ground potential is input to the IN / OUT pin 72.

  When the process cartridge 3 is mounted at the cartridge mounting position, the four terminals 75 to 78 of the main body side circuit 62 are elastically brought into contact with the terminals 95 to 98 of the cartridge side circuit 63, respectively. 63 is electrically connected. In this state, when the IN / OUT pin 72 is set to the signal input mode, a potential obtained by dividing the voltage (potential) of the Vcc pin 71 by the first resistor 85 and the second resistor 105 is input to the IN / OUT pin 72. .

  Therefore, whether or not the process cartridge 3 is mounted at the cartridge mounting position can be determined based on whether or not the potential input to the IN / OUT pin 72 is higher than a predetermined potential.

  Further, in a state where the main body side circuit 62 and the cartridge side circuit 63 are electrically connected, the IN / OUT pin 72 of the IC chip 51 is set to the signal output mode, and the IC chip 51 has the IN / OUT pin 72. A signal for controlling the display of the nonvolatile display 33 can be transmitted to the graphic chip 52 via the second wiring 82, the terminals 76 and 96, the sixth wiring 102, and the IN pin 92 of the graphic chip 52.

  Further, in a state where the main body side circuit 62 and the cartridge side circuit 63 are electrically connected, the IC chip 51 is connected to the OUT pin 94, the eighth wiring 104, the terminals 98 and 78, the fourth wiring 84, and the like from the graphic chip 52. Information such as the cartridge ID of the process cartridge 3 can be received via the IN pin 74.

  When the CPU 44 communicates between the IC chip 51 and the graphic chip 52, the CPU 44 controls a solenoid that is a driving source of the lock member 36 to displace the lock member 36 from the unlock position to the lock position. . This prohibits the separation of the process cartridge 3 from the cartridge mounting position in the housing 2, so that the connection between the main body side circuit 62 and the cartridge side circuit 63 is released during the communication between the IC chip 51 and the graphic chip 52. Can be suppressed, and interruption of communication can be suppressed.

<Effect>
As described above, the process cartridge 3 that accommodates toner that is consumed as a result of image formation is detachably attached to the housing 2. A non-volatile display 33 is attached to the process cartridge 3, and consumption information about the process cartridge 3 is displayed on the non-volatile display 33. The nonvolatile display 33 with the housing 2 attached to the process cartridge 3 is visible from the outside of the housing 2 through the viewing window 23 provided on the upper surface 15 of the housing 2. Therefore, the non-volatile display 33 can be visually recognized without accessing the inside of the housing 2 (without opening the front cover 14), so the consumption information displayed on the non-volatile display 33 can be easily confirmed from the outside of the housing 2. Is possible.

  For example, the remaining amount of toner stored in the process cartridge 3 is displayed on the non-volatile display 33. Therefore, the user can easily recognize the remaining amount of toner.

  Further, since the non-volatile display 33 can maintain the display of an image without receiving power supply, even when the process cartridge 3 is detached from the housing 2, there is a remaining amount of toner on the non-volatile display 33. It is displayed and the display content can be visually recognized by the user.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the above-described embodiment, the configuration in which the viewing window 23 is provided on the upper surface 15 of the housing 2 is taken up. However, the viewing window 23 is provided on the front cover 14 as shown in FIGS. 8 and 9. May be. In this case, the non-volatile display 33 is disposed at a position facing the viewing window 23 in the front-rear direction with the process cartridge 3 mounted in the cartridge mounting position in the housing 2.

  The configuration in which the viewing window 23 is provided on the upper surface 15 of the housing 2 has an advantage that the user can easily look into the viewing window 23 as compared with the configuration in which the viewing window 23 is provided on the front cover 14. The configuration in which the viewing window 23 is provided on the front cover 14 has an advantage that external light is less likely to enter the housing 2 from the viewing window 23 than the configuration in which the viewing window 23 is provided on the upper surface 15 of the housing 2. Have

  8 and the subsequent drawings, parts having functions equivalent to those of the respective parts described above are denoted by the same reference numerals as those given to the respective parts described above.

  Further, as shown in FIG. 9, a protrusion 25 is provided on the inner surface of the front cover 14. The protruding portion 25 has a rectangular portion 111 that is long in the left-right direction and a rectangular convex portion 112 that protrudes upward from the upper right end of the rectangular portion 111 when viewed from the front when the front cover 14 is closed. Is formed. Correspondingly, as shown in FIG. 10, the process cartridge 3 is formed with a recess 113 into which the protrusion 25 is fitted in a state in which the front cover 14 is closed. The non-volatile display 33 is disposed on the back side of the recess 113.

  With this configuration, the casing 2 of the printer 1 and the genuine process cartridge 3 can be associated with each other, and it is possible to suppress the use of a process cartridge that is not a genuine product mounted on the casing 2.

  However, the shape of the recess 113 does not have to be similar to the shape of the protrusion 25 as long as the protrusion 25 can be fitted as shown in FIG. In this case, the process cartridge 3 can be versatile.

  Moreover, the structure shown by FIG. 12 and FIG. 13 may be employ | adopted. In the configuration shown in FIGS. 12 and 13, a notch 121 that is cut out from the outside to the inside of the housing 2 is formed at the upper corner of the front right end of the housing 2. In place of the process cartridge 3, a toner box 122 (consumer storage unit, an example of a storage box) that stores toner is detachably attached to the notch 121.

  As shown in FIG. 13, a lock member 36 is provided on the side surface 123 facing the right side of the notch 121. With the toner box 122 mounted in the notch 121, the lock member 36 advances to the lock position, so that the lock member 36 engages with the lock recess 35 formed in the toner box 122, and the notch 121. From the toner box 122 is prohibited. When the lock member 36 is retracted from the lock position to the lock release position and the engagement between the lock recess 35 and the lock member 36 is released, the toner box 122 is allowed to be detached from the notch 121.

  Further, four terminals 75, 76, 77, 78 of the main body side circuit 62 are arranged in a line in the left-right direction on the side surface 124 facing the front side of the notch 121. Correspondingly, terminals 95, 96, 97, 98 of the cartridge side circuit 63 are provided on the side surface of the toner box 122. When the toner box 122 is attached to the notch 121, the four terminals 75 to 78 of the main body side circuit 62 are elastically brought into contact with the terminals 95 to 98 of the cartridge side circuit 63, respectively. 63 is electrically connected.

  Further, a toner supply port 126 is formed on the lower surface 125 of the notch 121. On the other hand, although not shown, a toner supply port is formed on the bottom surface of the toner box 122. With the toner box 122 mounted in the notch 121, the toner supply port overlaps and communicates with the toner supply port 126 from above, and the toner stored in the toner box 122 passes through the toner supply port and the toner supply port 126. Supply into the housing 2 is possible.

  The housing 2 is provided with a photosensitive drum and a developing device for supplying toner to the peripheral surface of the photosensitive drum, and the toner supplied into the housing 2 from the toner supply port 126 is developed. The container is to be replenished.

  A non-volatile display 33 is disposed on the upper surface 127 of the toner box 122. Therefore, the non-volatile display 33 can be viewed from the outside of the housing 2 without providing the viewing window 23 in the housing 2.

  Although a monochrome laser printer has been taken up as an example of the image forming apparatus, the present invention can also be applied to a color laser printer, and is not limited to a laser printer, and forms an image on a sheet by an inkjet method. An inkjet printer may be used. When the present invention is applied to an ink jet printer, an ink cartridge containing ink is an example of a storage box.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1: Printer 2: Housing 3: Process cartridge 13: Opening part 14: Front cover 15: Upper surface 23: Viewing window 24: Transparent member 25: Protruding part 31: Photosensitive drum 33: Non-volatile display 44: CPU
113: Concave part 121: Notch part 122: Toner box

Claims (12)

An image forming apparatus for forming an image on a sheet,
A housing,
A consumable agent storage unit that is detachably attached to the housing and that contains a consumable agent that is consumed as the image is formed;
A display that is attached to the consumable agent storage unit and displays consumption information about the consumable agent storage unit;
The image forming apparatus, wherein the casing is configured so that the display can be viewed from the outside. The image forming apparatus according to claim 1,
The consumable agent storage unit is an image forming apparatus that is a storage box that stores a printing agent used for image formation. The image forming apparatus according to claim 2,
The image forming apparatus, wherein the consumption information includes information related to a remaining amount of printing agent stored in the storage box. The image forming apparatus according to any one of claims 1 to 3,
Further comprising a cover attached to the housing so as to be openable and closable,
In the case,
Opened and closed by opening and closing the cover, and an opening through which the consumable agent storage part passes when being attached to and detached from the housing;
A viewing window is provided at a position facing the display in a state in which the consumable agent storage portion is mounted in the housing, and allows the inside and outside of the housing to communicate with each other while the opening is closed by the cover. An image forming apparatus. The image forming apparatus according to any one of claims 1 to 3,
The housing is provided with a notch cut out from the outer surface toward the inside,
The consumable agent storage part is detachably attached to the notch part, and its outer surface forms a part of the outer surface of the housing,
The image forming apparatus, wherein the display is disposed on an outer surface of the consumable material container. The image forming apparatus according to claim 4,
A photoconductor disposed in the housing and on which an electrostatic latent image corresponding to an image formed on a sheet is formed;
An image forming apparatus, further comprising: a light shielding member that is provided between the viewing window and the photoconductor and shields light incident from the viewing window toward the photoconductor. The image forming apparatus according to claim 4, further comprising a transparent member made of a transparent material and provided to close the viewing window. The image forming apparatus according to claim 4, 6 or 7,
A protrusion that protrudes from the periphery of the viewing window into the housing;
The consumable agent accommodating portion is formed with a concave portion having a shape corresponding to the outer shape of the protruding portion,
The display is an image forming apparatus disposed in the recess. The image forming apparatus according to any one of claims 4 and 6-8,
The housing has a side surface extending in the vertical direction and an upper surface connected to the upper end of the side surface,
The image forming apparatus, wherein the viewing window is provided on the upper surface of the housing. The image forming apparatus according to any one of claims 4 and 6-8,
The housing has a side surface extending in the vertical direction and an upper surface connected to the upper end of the side surface,
The image forming apparatus, wherein the viewing window is provided on the side surface of the housing. An image forming apparatus according to any one of claims 1 to 10,
The display is an image forming apparatus that is a non-volatile display capable of maintaining image display without receiving power. An image forming apparatus according to any one of claims 1 to 11,
A control unit provided in the housing and connected to the display so as to be communicable;
The control unit causes the display to display information other than the wear information.

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