JP2004160810A - Recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically detect stain of a linear encoder slit. <P>SOLUTION: A moving distance α1 when a carrier is scanned from a first position to a second position while the distance between a recording head and a platen is kept to be a first distance is measured. Then, at the second position after a moving distance α is measured, a moving distance -α2 is measured by scanning the carrier from the second position to the first position while the distance between the recording head and the platen is kept to be a second distance after the distance between the recording head and the platen is changed to the second distance. When α1-α2 is not larger than a predetermined value, the linear encoder slit is judged as normal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to control of a printing apparatus, and in particular, in order to make the distance between a print head and a recording medium appropriate, the thickness can be determined from the type of the recording medium and the carrier can be automatically moved up and down. The control of the recording device.
[0002]
[Prior art]
For example, as an information output device in a word processor, a personal computer, a facsimile, or the like, a recording device such as a printer that records desired information such as characters and images on a sheet-shaped recording medium such as paper or film is widely used. I have.
[0003]
As a recording method of such a recording apparatus, a thermal transfer method of transferring ink of an ink ribbon by thermal energy or an ink jet recording method of performing recording by flying ink droplets and attaching the ink droplets to a recording medium such as paper. Etc. are known.
[0004]
Among such recording methods, particularly, the ink jet recording method is a non-impact recording method that does not generate noise during recording, can perform high-speed recording, and records on a plain paper without requiring a special fixing process. Can be performed. In addition, since the device configuration is relatively simple, colorization is easy.
[0005]
In an ink jet recording apparatus having such advantages, the distance between the recording head and the recording medium (inter-paper distance) is made as small as possible so as not to be in contact with each other, so that ink droplets can be accurately attached to the recording medium. And high-accuracy recording can be realized.
[0006]
Therefore, there are a number of products on the market that enable the recording head to be moved up and down with respect to the platen in accordance with the thickness of the recording medium. Many of them are provided with a manual paper interval adjusting lever.
[0007]
On the other hand, some inkjet recording apparatuses arrange a linear encoder slit within a movable range of a carrier and servo-control a carrier motor while reading this linear encoder slit with an encoder sensor arranged on the carrier. . This method has an advantage that noise can be suppressed as compared with a method using a stepping motor (Patent Document 1).
[0008]
[Patent Document 1]
JP-A-2002-096528
[0009]
[Problems to be solved by the invention]
However, in the above-described inkjet recording apparatus using the linear encoder slit, the encoder slit is contaminated during assembly work in a factory, the slit is contaminated when the user replaces the ink tank, or the recording head recovers. If the scattered ink adheres to the slits, the encoder sensor will skip the slits, so that the carrier position detection will be inaccurate and the printing position will be shifted laterally.
[0010]
The present invention has been made in order to solve the above-described problems of the related art, and an object of the present invention is to provide a recording apparatus that uses a linear encoder slit, a recording apparatus that can automatically detect contamination of the linear encoder slit. It is to provide a device.
[0011]
[Means for Solving the Problems]
To achieve the above object, a recording apparatus according to an embodiment of the present invention has the following configuration. That is, a scale provided with a plurality of indices at predetermined intervals, a sensor for reading the indices and detecting positional information of the measurement object, a recording head for recording on a recording medium on a platen, the sensor and the recording An image recording apparatus comprising: a carrier configured to hold a head and to be movable along the scale; and a carrier elevating unit that changes a distance between the recording head and the platen. First distance information reading means for moving the carrier by a predetermined distance while maintaining the distance to the platen at a first distance, reading first distance information relating to the distance from the sensor, and storing the first distance information in a memory; The carrier is moved by the predetermined distance while keeping the distance between the carrier and the platen at a second distance, and second distance information on the distance is obtained. Second distance information reading means for reading from the sensor and storing it in a memory; determining means for determining whether or not the scale is operating normally based on the first distance information and the second distance information; It is characterized by having.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to a scale provided with a plurality of indices at predetermined intervals, a sensor for reading the indices and detecting positional information of a measurement object, a recording head for recording on a recording medium on a platen, a sensor and a recording head A carrier configured to be movable along the scale, and a carrier elevating unit that changes the distance between the recording head and the platen, wherein the distance between the recording head and the platen A first distance information reading unit that moves the carrier by a predetermined distance while holding the distance at a distance, reads first distance information relating to the distance from a sensor, and stores the information in a memory, and sets a distance between the recording head and the platen to a second distance. A second distance information reading unit that moves the carrier by a predetermined distance while holding the distance, reads second distance information relating to the distance from a sensor, and stores the second distance information in a memory; Information and can be implemented as a recording apparatus characterized by comprising: a determination unit which determines whether the scale is operating normally, the based on the second distance information.
[0013]
Such an invention can be realized in the configuration specifically shown in FIGS. 1 to 12 in correspondence with the following first embodiment.
[0014]
<First embodiment>
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0015]
In this specification, “recording” (sometimes referred to as “printing” or “printing”) refers not only to the formation of significant information such as characters and figures, but also to human beings, Regardless of whether or not the image is visibly exposed, a case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or a medium is processed is also described.
[0016]
In addition, the term “recording medium” refers to not only paper used in general recording devices, but also a wide range of materials that can accept ink, such as cloth, plastic films, metal plates, glass, ceramics, wood, and leather. Shall be.
[0017]
Further, “ink” (sometimes referred to as “liquid”) is to be interpreted broadly as in the definition of “recording (printing)”, and when applied on a recording medium, an image or pattern , Or a liquid that can be used for forming a pattern or the like, processing a recording medium, or processing ink (for example, coagulation or insolubilization of a colorant in ink applied to a recording medium).
[0018]
Hereinafter, as an embodiment of the present invention, a recording system including a recording apparatus that performs recording according to an inkjet method and a personal computer that is a host apparatus that transmits image data to the recording apparatus will be described as an example.
[0019]
[Inkjet printer: Fig. 1]
FIG. 1 is a front view of an ink jet printer as an embodiment of the present invention. A carrier 102 having a recording head 101 is movable along a carrier shaft 105 held by a left plate 103 and a right plate 104, and is controlled via a carrier belt 107 by driving a carrier motor 106. Is done. Further, an encoder sensor 108 is provided on the carrier 102. The encoder sensor 108 reads a position difference from a reference position from a linear encoder slit 109 (a scale provided with a scale serving as an index of a plurality of positions at predetermined intervals) held by the left side plate 103 and the right side plate 104. , A sensor for detecting the current position of the carrier 102. In other words, the linear encoder slit 109 and the encoder sensor 108 constitute a linear encoder that detects positional information of the measurement object, but the scale interval, the size of the scale, and the like may be arbitrarily designed according to the recording device. Can be.
[0020]
On the other hand, the drive of the paper feed motor 110 is transmitted to the paper feed roller 111, and the recording medium sandwiched between the paper feed roller 111 and the pinch roller 112 can be transported onto the platen 113. . The recovery device 116 includes a cap member, a wipe member, a suction pump, and the like, and performs maintenance for the recording head 101 and protects the recording head 101 when not in use.
[0021]
[Left plate: Fig. 2]
FIG. 2 is a diagram illustrating the left side plate 103 in detail. Near the center of the left side plate 103, there is a vertically long rectangular hole for holding the carrier shaft 105, and its width is substantially equal to the diameter of the carrier shaft 105. In addition, a linear encoder slit 109 is held above the left side plate 103.
[0022]
[Carrier elevating device in lift-down state: FIG. 3]
FIG. 3 is a diagram illustrating a carrier elevating device provided on the left side plate 103 in a lift-down state (a state where the carrier shaft is lowered). When the carrier lifting / lowering member 115 is moved forward by the driving of the carrier lifting / lowering motor 114, the carrier shaft 105 can be lowered along the hole shape.
[0023]
[Inkjet printer in lift-down state: Fig. 4]
FIG. 4A is a side view of the inkjet printer in a lift-down state. Since the carrier 102 is in a lift-down state together with the carrier shaft 105, the distance L2 (second distance) between the recording head 101 and the platen 113 is in a "narrow" state. When the thickness of the recording medium is small, the recording operation is performed in this state. Further, since the encoder sensor 108 is also in the lift-down state, the position of the carrier 102 is detected by reading the lower side 109-2 of the linear encoder slit 109 as shown in FIG.
[0024]
[Carrier lifting device in lift-up state: FIG. 5]
FIG. 5 is a diagram illustrating a carrier lifting device provided on the left side plate 103 in a lift-up state (a state in which the carrier shaft is raised). When the carrier lifting / lowering member 115 is moved backward by driving the carrier lifting / lowering motor 114, the carrier shaft 105 can be raised along the hole shape.
[0025]
[Inkjet printer in lift-up state (side view: Fig. 6)]
FIG. 6A is a side view of the inkjet printer in a lift-up state. Since the carrier 102 is in the lift-up state together with the carrier shaft 105, the distance L1 (first distance) between the recording head 101 and the platen 113 is "wide". When the thickness of the recording medium is large, the recording operation is performed in this state. Since the encoder sensor 108 is also in the lift-up state, the position of the carrier 102 is detected by reading the upper side 109-1 of the linear encoder slit 109, as shown in FIG.
[0026]
[Inkjet printer in lift-up state (front): Fig. 7]
FIG. 7 is a front view of the inkjet printer in a lift-up state.
Since the carrier 102 is in a lift-up state together with the carrier shaft 105, the carrier belt 107 is slightly extended, but no trouble occurs in driving by the carrier motor 106.
The mechanism described so far on the left side is provided in the same manner on the right side.
[0027]
[Control Configuration of Inkjet Printer: FIG. 8]
FIG. 8 is a block diagram illustrating a control configuration of the inkjet printer according to the present embodiment. Data of an image to be recorded is input from the personal computer 211 to the reception buffer 301 of the printer 200. Further, data for confirming whether data is correctly transferred and data for notifying the operation state of the printer 200 are transmitted from the printer 200 to the personal computer 211. The data in the reception buffer 201 is transferred to the memory unit 203 under the control of the CPU 202, and is temporarily stored in a RAM (random access memory) of the memory unit 203. The mechanical control unit 204 controls driving of a mechanical unit 205 such as a carrier motor or a paper feed motor in accordance with a command from the CPU 202. The sensor / SW control unit 206 sends signals from the sensor / SW unit 207 including various sensors and SWs (switches) to the CPU 202. The display element control unit 208 controls a display element unit 209 including an LED, a liquid crystal element, and the like of the display panel group according to a command from the CPU 202. The printhead control unit 210 controls the printhead 101 according to a command from the CPU 202. The printhead control unit 210 detects temperature information and the like indicating the state of the printhead, and sends them to the CPU 202.
[0028]
[Check process of linear encoder slit state: Fig. 9]
FIG. 9 is a flowchart for explaining the flow of a process in which the printer 200 checks the state of the linear encoder slit 109. FIG. 10 shows the positional relationship between the linear encoder slit 109 and the encoder sensor 108 in the process. FIG. This process is realized by the CPU 202 executing a program stored in the ROM of the memory unit 203. This sequence is performed immediately after the power of the printer is turned on.
[0029]
First, in step 1001, the carrier lifting motor 114 is driven to lift down the carrier 102.
[0030]
In step 1002, the carrier motor 106 is driven to abut the carrier 102 on the right end. This results in the state shown in FIG. 10A (carrier position: first position).
[0031]
In step 1003, the position information detected by the encoder sensor 108 is read and assigned to a variable E1.
[0032]
In step 1004, the carrier lifting motor 114 is driven to lift up the carrier 102. This results in the state shown in FIG. 10B (carrier position: first position, distance L1 (wide) between recording head 101 and platen 113: first distance, see FIG. 6).
[0033]
In step 1005, the carrier motor 106 is driven to hit the carrier 102 to the left end. This operation results in the state shown in FIG. 10C (carrier position: second position, distance L1 (wide): first distance between recording head 101 and platen 113). In this process, the encoder sensor 108 moves while detecting the upper side of the linear encoder slit 109.
[0034]
In step 1006, the carrier lifting motor 114 is driven to lift down the carrier 102. This results in the state shown in FIG. 10D (carrier position: second position, distance L2 (narrow) between recording head 101 and platen 113: second distance, see FIG. 4).
In step 1007, the carrier motor 106 is driven to abut the carrier 102 on the right end. This operation results in the state shown in FIG. 10E (carrier position: first position, distance L2 (narrow) between recording head 101 and platen 113: second distance). In this process, the encoder sensor 108 moves while detecting the lower side of the linear encoder slit 109.
[0035]
In step 1008, the position information detected by the encoder sensor 108 is read and assigned to a variable E2.
[0036]
In step 1009, the absolute value of the variable (E1-E2) is calculated, and it is determined whether the absolute value is equal to or less than a predetermined value. If it is determined that the value is equal to or smaller than the predetermined value, it is determined that there is no abnormality in the slit, and the process ends. If it is determined that it is not less than the predetermined value, it is determined that there is an abnormality in the slit, and the process proceeds to step 1010.
[0037]
In step 1010, a linear encoder slit error is displayed, and the process ends.
[0038]
[Example of linear encoder slit without abnormality: Fig. 10]
How the above-described processing is determined when the linear encoder slit 109 having no abnormality is actually performed will be described with reference to FIG. 10 as an example.
[0039]
Note that the example shown in FIG. 10 is an example, and another method may be used.
[0040]
For example, in the processing of FIGS. 10A to 10C, the carrier 102 is arranged at the first position shown in FIG. 10A, the carrier is lifted up at the first position, and then the carrier 102 is moved to the first position. To the second position shown in FIG. 10 (c), and the movement distance α1 at this time is measured using the upper part of the linear encoder slit 109 (scale), and FIG. 10 (d) to FIG. In the processing of (), the carrier 102 is lifted up at the second position shown in FIG. 10C, and then the carrier 102 is moved from the second position to the first position shown in FIG. The distance -α2 is measured using the lower part of the linear encoder slit 109 (scale).
[0041]
That is, in the example shown in FIG. 10, the carrier 102 is the same using different portions of the scale of the linear encoder slit 109 (the lower side 109-2 shown in FIG. 4B and the upper side 109-1 shown in FIG. 6B). The distance (α1, α2) when the distance (α1, α2, α1 = α2) is moved is measured twice, and the normal / abnormal of the linear encoder slit 109 is determined depending on whether the measurement results are the same or different. is there. Therefore, for example, after performing the processes of FIGS. 10A to 10C (measurement using the upper portion of the encoder slit 109), the carrier 102 is returned to FIG. After the carrier lift-down at the position, the processing of FIGS. 10A to 10C (measurement using the lower portion of the encoder slit 109) may be performed again.
[0042]
Hereinafter, FIG. 10 will be described in detail.
[0043]
In step 1003, when the position information (E1) of the encoder sensor 108 read in the state shown in FIG. 10A is reached, in step 1005, when the state shown in FIG. As the carrier moves while detecting the upper side of 109, a value (E1 + α1) changed by the amount (α) of movement of the carrier 102 is detected (the position information of the encoder sensor 108 read in the state of FIG. E2) = E1 + α1).
[0044]
Further, in step 1008, when the state shown in FIG. 10E is reached, the encoder sensor 108 moves while detecting the lower side of the linear encoder slit 109, and thus changes by the amount (−α2) of the movement of the carrier 102 during that time. The calculated value (E1 + α1−α2) is read and substituted for the variable E2. Here, since the carrier 102 is moved by the same distance (α1 = α2), as a result, FIG. 10E when the carrier 102 moves as shown in FIG. 10A → FIG. 10C → FIG. The position information (E2) of the encoder sensor 108 read at the indicated first position is E2 = E1, and in the determination in step 1009, the absolute value (E1-E2) = 0, and it is correctly determined that there is no abnormality in the slit. Is done.
[0045]
In the operation of reading the value of the encoder sensor 108 by abutting the carrier 102 on the right side plate 104, a value different by a few slits may be read every trial due to the elasticity of the carrier 102 and the right side plate 104. The limit is set to a predetermined value and used for the determination in step 1009.
[0046]
Next, a description will be given of how the determination is made when the measurement is performed on the linear encoder slit 109 having an abnormality.
[0047]
[Example of abnormal linear encoder slit: Fig. 11]
FIG. 11 is a first example of the linear encoder slit 109 having an abnormality. When the user performs the ink replacement work, the grease applied to the carrier shaft 105 is touched and the hand touches the linear encoder slit 109, so that the grease stain 301 has adhered to the lower side. The processing for this will be described.
[0048]
In step 1003, when the position information (E1) of the encoder sensor 108 read in the state shown in FIG. 10A is reached, in step 1005, when the state shown in FIG. Since the carrier moves while detecting the upper side of 109, a value (E1 + α1) changed by an amount (α1) by which the carrier 102 has moved is detected.
[0049]
Further, in step 1008, when the state of FIG. 10E is reached, the encoder sensor 108 moves while detecting the lower side of the linear encoder slit 109, so that the amount of movement of the carrier 102 during that time (−α2) A value (E1 + α1−α2 + β) that is insufficient for the width (β) at which the slit cannot be read due to dirt is read and substituted into the variable E2. Here, since the carrier 102 has been moved by the same distance (α1 = α2), as a result, E2 = E1 + β, so that in the determination in step 1009, the absolute value (E1-E2) = β, and there is an abnormality in the slit. Is determined. As a result, in step 1010, a linear encoder slit error is displayed.
[0050]
[Another example of abnormal linear encoder slit: Fig. 12]
FIG. 12 shows a second example of the abnormal linear encoder slit 109. In the course of the recovery operation of the recording head 101 by the recovery device 116, ink scatters from the wipe member and adheres to the linear encoder slit 109, so that the ink stain 302 adheres to the lower side. Here, assuming that the width (β) at which the slit cannot be read due to dirt is β = β1 + β2 as shown in FIG. 12, the processing for this is exactly the same as in FIG. 11, and it is determined that there is an abnormality in the slit. You.
[0051]
As described above, according to the present embodiment, it is possible to provide a recording apparatus capable of automatically detecting dirt on the linear encoder slit.
[0052]
The timing at which the dirt detection process is performed is not limited to immediately after the power of the printer is turned on. It may be performed at the factory inspection before shipment, may be performed immediately after the user opens and closes the printer cover for ink replacement or paper jam, or may be performed immediately after the printer performs recovery operation. You may go.
[0053]
Further, the width moved for detection is not limited to the left end to the right end. Immediately after the user opens and closes the printer cover for ink replacement or paper jam, etc., detection is performed only from the right end to the left end of the potentially dirty printer opening to save time. The detection may be performed, or immediately after the recovery operation is performed, the detection may be performed only in the vicinity of the recovery device to shorten the time.
[0054]
When an abnormality is detected in the linear encoder slit, not only the linear encoder error is displayed, but also error information is notified to the personal computer and the user is instructed on the monitor of the personal computer to clean the linear encoder slit. May be output, or the detection may be repeated by gradually reducing the moving width to specify the dirty portion, and the carrier may be stopped there to indicate the dirty position to the user.
[0055]
[Other embodiments]
The above-described embodiment includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for causing ink to be ejected, particularly in an ink jet recording system. It is preferable to use a method that causes a change in the state.
[0056]
The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, and the like), but can be applied to an apparatus (for example, a copying machine and a facsimile device) including one device. May be applied.
[0057]
Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and a computer (or CPU or MPU) of the system or apparatus to store the storage medium. It is needless to say that the present invention can also be achieved by reading and executing the program code stored in the program.
[0058]
In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code and the program itself constitute the present invention.
[0059]
As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. be able to.
[0060]
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. It goes without saying that a part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0061]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that a CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0062]
When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the above-described flowchart (shown in FIG. 9).
[0063]
As described above, in the recording apparatus according to the embodiment of the present invention, a plurality of indices are arranged on the scale at predetermined intervals in a direction orthogonal to the moving direction of the carrier, and the first distance information and the second distance information are indices. It is preferable that the information is obtained by measuring each side having a different relative position with respect to the sensor.
[0064]
Further, for example, it is preferable that the first distance information is information obtained by measuring an upper position of the index by the sensor, and the second distance information is information obtained by measuring a lower position of the index by the sensor.
[0065]
Further, for example, the first distance information reading unit may be configured to scan the carrier from the first position to the second position while maintaining the distance between the recording head and the platen at the first distance. The information on the distance is stored as the first distance information, and the second distance information reading unit changes the distance between the recording head and the platen to the second distance at the second position after measuring the first distance information, and performs the recording. Information about the distance from the second position to the first position when the carrier is scanned from the second position to the first position while maintaining the distance between the head and the platen at the second distance is stored as second distance information. Is preferred.
[0066]
Further, for example, the determining unit compares the first distance information and the second distance information, and determines that the scale is operating normally if the difference between the first distance information and the second distance information is less than a predetermined amount. Is preferred.
[0067]
Further, for example, when the determining unit determines that the scale is not operating normally, it is preferable to notify that the scale is abnormal.
[0068]
Further, for example, it is preferable that the recording head is an inkjet recording head that performs recording by discharging ink.
[0069]
【The invention's effect】
As described above, according to the present invention, in a recording apparatus using a linear encoder slit, it is possible to provide a recording apparatus capable of automatically detecting dirt on the linear encoder slit.
[Brief description of the drawings]
FIG. 1 is a front view of an ink jet printer as an embodiment of the present invention.
FIG. 2 is a diagram illustrating a left side plate in detail.
FIG. 3 is a diagram illustrating a carrier elevating device provided on a left side plate in a lift-down state.
4A is a side view of the inkjet printer in a lift-down state, and FIG. 4B is a diagram illustrating a measurement position of a linear encoder slit.
FIG. 5 is a diagram illustrating a carrier elevating device provided on a left side plate in a lift-up state.
FIG. 6A is a side view of the inkjet printer in a lift-up state, and FIG. 6B is a diagram illustrating a measurement position of a linear encoder slit.
FIG. 7 is a front view of the inkjet printer in a lift-up state.
FIG. 8 is a block diagram of the ink jet printer of the embodiment.
FIG. 9 is a flowchart illustrating a flow of a process in which a printer checks a state of a linear encoder slit.
FIG. 10 is a diagram illustrating a positional relationship between a linear encoder slit and an encoder sensor in the process of FIG. 9;
FIG. 11 is a first example of an abnormal linear encoder slit.
FIG. 12 is a second example of an abnormal linear encoder slit.
[Explanation of symbols]
101 Recording head
102 career
103 Left side plate
104 Right side plate
105 carrier shaft
106 Carrier motor
107 carrier belt
108 linear encoder slit
109 Encoder sensor
110 Paper feed motor
111 paper feed roller
112 Pinch roller
113 Platen
114 Carrier elevating motor
115 Carrier elevating member
116 Recovery device
301 Grease stain
302 Ink stain

Claims (1)

A scale provided with a plurality of indices at predetermined intervals, a sensor that reads the indices and detects position information of the measurement target, a recording head that records on a recording medium on a platen, the sensor and the recording head, A recording apparatus comprising: a carrier configured to be movable along the scale, and a carrier elevating unit that changes a distance between the recording head and the platen.
First distance information reading means for moving the carrier by a predetermined distance while maintaining the distance between the recording head and the platen at a first distance, reading first distance information relating to the distance from the sensor, and storing it in a memory; ,
A second distance information reading unit that moves the carrier by the predetermined distance while maintaining a distance between the recording head and the platen at a second distance, reads second distance information relating to the distance from the sensor, and stores the second distance information in a memory; When,
Determining means for determining whether or not the scale is operating normally based on the first distance information and the second distance information;
A recording device comprising:

Images