JP6020086B2 - Thickness measuring device - Google Patents

Description

  The present invention relates to a thickness measuring apparatus.

  2. Description of the Related Art Conventionally, image forming apparatuses such as printers, copiers, and multifunction machines are provided with a thickness measuring device for measuring the thickness of a sheet that is a storage medium for printing. Thickness measurement methods include, for example, a thickness measurement roller that is displaced by the thickness of the paper as it passes, and measures the distance displaced directly by a detection sensor that contacts the thickness measurement roller. In general, a method of measuring by a magnetic amount that changes with displacement of a roller for measuring thickness is generally used.

  In addition, it is not necessary to detect the thickness of all the sheets, and if the condition that the continuously conveyed sheets are of the same type is given, only the first sheet is detected. It is sufficient to measure. The configuration of a thickness measurement sensor or the like for measuring the thickness may decrease the detection accuracy due to wear as the chance of contacting the thickness detection roller increases. Therefore, for example, as in the image forming apparatus described in Patent Document 1, by providing a drive mechanism such as a motor or a solenoid, when there is no need for measurement, the thickness detection sensor and the roller are separated from each other. It is shown.

  However, providing a drive mechanism using a solenoid or the like as described above is not preferable because an increase in the number of parts and an arrangement space for the mechanism are required.

  This invention is made | formed in view of the above, Comprising: It aims at achieving space saving of a thickness measuring apparatus.

  In order to solve the above-described problems and achieve the object, the present invention is provided in a thickness direction of the paper by contacting the paper with a conveyance roller that conveys the paper and the conveyance roller. A thickness detecting roller configured to be displaceable toward the head, and a thickness detecting unit that has an operating portion that contacts the thickness detecting roller, and detects a displacement amount of the thickness detecting roller in a contact manner from a displacement amount of the operating portion; A thickness calculation unit that calculates the thickness of the paper from the detected displacement amount of the thickness detection roller, and an energization control unit that energizes either the thickness detection roller or the operating unit. The thickness detection roller or the operating part is provided with an electromagnet, the other is made of a magnetic material, and the energization control unit includes the thickness detection roller and the operating part. Out of The side on which the recording magnet is provided is energized when measuring the thickness of the paper, and is controlled not to be energized except when measuring the thickness of the paper, and the operating portion and the thickness The detection rollers are in contact with each other while the energization is being performed, and the operating unit is displaced following the displacement of the thickness detection roller, and while the energization is not being performed, the detection rollers are It is separated, and even if the thickness detection roller is displaced, the operating part is not displaced.

  According to the present invention, there is an effect that space saving of the thickness measuring device can be achieved.

FIG. 1 is a side sectional view showing a hardware configuration of an image forming apparatus according to an embodiment. FIG. 2 is a diagram illustrating a thickness measuring device provided in the image forming apparatus of the embodiment. FIG. 3 is a diagram illustrating a thickness measuring device provided in the image forming apparatus of the embodiment. FIG. 4 is a diagram illustrating a thickness measuring device provided in the image forming apparatus of the embodiment. FIG. 5 is a diagram illustrating a thickness measuring device provided in the image forming apparatus of the embodiment. FIG. 6 is a timing chart showing the paper detection sensor of the embodiment and the timings of energization and thickness detection.

  Exemplary embodiments of a thickness measuring device according to the present invention as an image forming apparatus will be described below in detail with reference to the accompanying drawings. Note that the image forming apparatus corresponds to an apparatus that transports paper such as a copier, a FAX, a printer, and a multifunction peripheral in which these are integrated. Further, the medium to be conveyed may be other than the paper. FIG. 1 is a side sectional view of an image forming apparatus 100 according to the first embodiment. As shown in FIG. 1, the image forming apparatus 100 includes a paper feeding device 200, a print medium conveying device 300, a thickness measuring device 400, a secondary transfer device 500, an image carrier 600, and a fixing device 700.

  The image carrier 600 is a four-color image carrier 600Y, 600M, 600C, or 600Bk of yellow, magenta, cyan, and black. Further, the image forming apparatus 100 includes an intermediate transfer belt 501. The toner images formed by the image carriers 600Y, 600M, 600C, and 600Bk are transferred to the intermediate transfer belt 501.

  The paper feeding device 200 feeds paper from the paper feeding trays 201 a and 201 b to the printing medium transport device 300. Sheets S are stacked on the sheet feed trays 201a and 201b. The paper S fed from the paper feeding device 200 is transported to the print medium transport device 300. The print medium conveyance device 300 includes a conveyance path 301 and a conveyance roller pair 302. The conveyance path 301 is configured by a guide plate, and the sheet S is conveyed along the conveyance path 301. The conveyance path 301 is configured to sandwich the paper S from both the upper surface and the lower surface of the paper S. A plurality of conveyance roller pairs 302 are provided in the conveyance path 301, rotate by being driven with a rotation shaft as a fulcrum, and convey the sheet S sandwiched between the rollers.

  The sheet S is transported along the transport path 301 to the secondary transfer device 500. Then, the secondary transfer device 500 transfers the toner image formed on the intermediate transfer belt 501 onto the paper S. Next, the fixing device 700 fixes the toner image transferred to the paper S, and the paper S is discharged from the image forming apparatus 100.

  FIG. 2 is a diagram illustrating a detailed configuration of the thickness measuring apparatus 400. As shown in FIG. 2, the thickness measuring device 400 includes a thickness detection sensor 1 (thickness detection unit), a thickness detection roller 2, an operation unit 4, a fixed roller 5 (conveyance roller), and a paper detection sensor 6 (paper detection unit). ). The thickness detection roller 2 is installed in the conveyance path 301 so as to face the fixed roller 5, and is movable perpendicularly to the conveyance direction of the paper S (thickness direction of the paper S). On the other hand, the fixed roller 5 is fixed so as not to move perpendicularly to the transport direction, and transports the paper S. The thickness detection sensor 1 measures a displacement amount of the thickness detection roller 2 in a direction perpendicular to the conveyance direction of the paper S in a contact manner. The operating unit 4 is a member constituting the thickness detection sensor 1, and the thickness of the paper S is detected based on the amount of displacement of the operating unit 4. Further, on the upstream side of the conveyance path 301 with respect to the installation position of the thickness detection roller 2, for example, a paper detection sensor 6 configured by a reflective photosensor is installed.

  As the thickness detection sensor 1, for example, a lever type encoder sensor or the like is used. When the sheet S is passing between the fixed roller 5 and the thickness detection roller 2, if the thickness detection roller 2 or the operating shaft of the thickness detection roller 2 is pushed up by the sheet S, the lever-type encoder of the thickness detection sensor 1 is used. And the thickness detecting sensor 1 can measure the amount of displacement of the thickness detecting roller 2 and the like. FIG. 3 shows a detailed configuration of the thickness detection sensor 1, and FIG. 4 is a diagram showing an operation of the thickness detection sensor 1.

  FIG. 3A is a cross-sectional view of the thickness detection sensor 1. In the thickness detection sensor 1, a slit 7 is formed on one side of the operating part 4. When the operating part 4 is displaced, the slit 7 rotates, and the encoder 8 measures the amount of rotation. Further, as shown in FIG. 3B, the thickness detection sensor 1 includes an operating portion 4 and a casing 10 of the thickness detection sensor 1 fixed by an elastic portion 9 such as a spring, and after the operating portion 4 operates. It is configured to return to the original position by the elastic force of the spring. Note that one of the operating unit 4 and the thickness detection roller 2 includes an electromagnet, and the other is formed of a magnetic material. In the present embodiment, it is assumed that the operating unit 4 is provided with an electromagnet and the thickness detection roller 2 is made of a magnetic material. In a state where no current flows through the electromagnet, the operating unit 4 is held without contact with the thickness detection roller 2 by the elastic force of the elastic unit 9 as shown in FIG. Has been. On the other hand, in a state where a predetermined amount or more of current flows through the electromagnet, the operating portion 4 of the lever encoder sensor and the thickness detection roller 2 are attracted to and contact each other by the generated magnetic force. Therefore, in a state where current flows through the electromagnet, the thickness detection roller 2 is displaced by the thickness of the sheet S, and the operating unit 4 in contact with the thickness detection sensor 1 is also displaced by the thickness. The thickness of S can be measured.

  FIG. 5 is a block diagram illustrating a functional configuration of the image forming apparatus 100. The image forming apparatus 100 newly includes a CPU 11, a storage unit 12, an energization control unit 13, and a thickness calculation unit 14. The CPU 11 performs overall control of the image forming apparatus 100, has various chip sets, and is connected to other devices via the chip sets. The storage unit 12 is a read-only memory used as a program / data storage memory, a write / read memory used as a program / data development memory, a printer drawing memory, or the like. The energization control unit 13 determines whether or not to energize the electromagnet provided in the operating unit 4, and performs energization according to the determination. The timing for energizing the electromagnet is triggered by the detection of the paper by the paper detection sensor 6. The thickness calculator 14 calculates the thickness of the paper S based on the displacement amount of the operating unit 4 detected by the thickness detection sensor 1. A method for calculating the thickness will be described later.

  FIG. 6 is a timing chart showing the output of the paper detection sensor 6, the timing of energization, and the output of the thickness detection sensor 1. As shown in FIG. 6, the paper detection sensor 6 outputs a detection signal at time t1 when the paper S is detected. The energization control unit 13 calculates a time t3 (arrival time) for the sheet S to reach the thickness detection roller 2 from t1 as a base point, and the thickness detection sensor 1 and the thickness detection roller 2 are connected at time t2 before ty from t3. A current starts to flow after tx of t1 so that a current equal to or greater than a predetermined current value X, which is predetermined in order to generate a magnetic force for contact, flows in the electromagnet. That is, the period of t1 + tx−t2 corresponds to the energization preparation time in this embodiment. By controlling in this way, unnecessary energization is not performed except for the time used for the actual measurement of the thickness of the paper S, thereby suppressing power consumption and reducing the thickness between the thickness detection sensor 1 and the thickness detection roller 2. The contact time can be reduced as much as possible.

  The energization control unit 13 may start energizing the current when the paper detection sensor 6 detects the paper S. In addition, the energization control unit 13 sets t5, which is the timing of stopping energization, to be a predetermined period from the timing of energization start, or ends by receiving a notification of completion of thickness calculation from the thickness calculation unit 14. Set. Alternatively, information on the conveyance speed of the sheet S may be acquired, and t3 may be calculated depending on how long it takes from the detection timing to the thickness detection roller 2 by the sheet detection sensor 6. Further, t5 may be calculated by calculating the time until the paper S passes the thickness detection roller 2 by dividing the length of the paper S in the transport direction by the transport speed of the paper S.

  When an electric current of X or more flows through the electromagnet, the operating unit 4 of the thickness detection sensor 1 and the thickness detection roller 2 are in contact with each other during the period t2-t3. In this state, the roller 2 is not reached. The thickness calculation unit 14 calculates the sensor reference value A by averaging the output values of the thickness detection sensor 1 during the period t2-t3. The sensor reference value A is an initial value of an output value generated when the thickness detection sensor 1 comes into contact with the thickness detection roller 2.

  Further, during the period from t3 to t5 during which the sheet S passes under the thickness detection roller 2, the thickness detection roller 2 and the operating unit 4 of the thickness detection sensor 1 are in contact with each other, and the thickness detection is performed. The roller 2 is in contact with the paper S. The thickness calculation unit 14 calculates the output average value B by averaging the output values in a predetermined period of t4-t5 when the output value of the thickness detection sensor 1 is most stable. Moreover, the thickness calculation part 14 may calculate the output average value B by averaging the output value of the whole period of t3-t5.

  Then, the thickness calculation unit 14 obtains the thickness of the paper S by subtracting the sensor reference value A from the calculated output average value B. The thickness of the sheet S calculated in this way is used, for example, when determining whether or not the sheets S are transported in an overlapping manner. For example, when the measured size of the previous sheet S is N, and when the newly measured size of the sheet S is 2N or more, it is determined that the sheets S are overlapped. Is stopped, and a process of issuing a warning to the user is executed. Thus, by using the average of the output values for the thickness measurement, it is possible to suppress measurement errors caused by errors in the shape of the thickness detection roller 2 and the like. In calculating the thickness, in addition to using the average value as described above, a measured value detected at a certain predetermined timing can be calculated as the thickness.

  Then, at the timing t5 when the calculation of the thickness of the sheet S is completed and the measurement of the thickness of the sheet S becomes unnecessary, the energization control unit 13 stops supplying current to the electromagnet provided in the operating unit 4. The thickness detection sensor 1 and the thickness detection roller 2 are separated from each other, so that deterioration of the sensor due to contact when thickness measurement is unnecessary can be suppressed.

  In the thickness measuring apparatus 400 of the present embodiment shown above, since one of the thickness detection roller 2 or the thickness detection sensor 1 includes an electromagnet and the other is made of a magnetic material, the electromagnet is energized. In this way, they can be brought into contact with each other. Therefore, it is not necessary to provide a separate mechanism for driving at least one of the thickness detection roller 2 and the thickness detection sensor 1 such as a solenoid, and the thickness measuring device 400 can be saved in space. .

DESCRIPTION OF SYMBOLS 1 Thickness detection sensor 2 Thickness detection roller 4 Operating part 5 Fixed roller 6 Paper detection sensor 7 Slit 8 Encoder 9 Elastic part 10 Case 12 Storage part 13 Current supply control part 14 Thickness calculation part 100 Image forming apparatus 200 Paper feeding apparatus 201a, 201b Paper feed tray 300 Print medium conveying device 301 Conveying path 302 Conveying roller pair 400 Thickness measuring device 500 Secondary transfer device 501 Intermediate transfer belt 600 Image carrier 600Y, M, C, Bk Image carrier 700 Fixing device 1000 Image forming device

JP 2002-195802 A

Claims (5)

A transport roller for transporting paper,
A thickness detecting roller provided opposite to the conveying roller and configured to be displaceable in a thickness direction of the paper by contacting the paper;
A thickness detecting unit that has an operating portion that contacts the thickness detecting roller, and detects a displacement amount of the thickness detecting roller in a contact manner from a displacement amount of the operating portion;
A thickness calculating unit that calculates the thickness of the paper from the detected displacement of the thickness detection roller;
An energization control unit for energizing either the thickness detection roller or the operating unit;
With
Either one of the thickness detection roller or the operating part is provided with an electromagnet, and the other is made of a magnetic material.
The energization control unit energizes the thickness detection roller and the side of the operating unit on which the electromagnet is provided when measuring the thickness of the paper, and other than when measuring the thickness of the paper Controls not to energize,
The operating part and the thickness detection roller are in contact with each other during the energization, and the operation part is displaced following the displacement of the thickness detection roller, and the energization is performed. The thickness measuring apparatus is characterized in that the operating portion is not displaced even when the thickness detecting roller is displaced, while the operating portion is not displaced even when the thickness detecting roller is displaced. The thickness calculation unit calculates the thickness of the paper by averaging the displacement amount of the thickness detection roller detected by the thickness detection unit while the energization is performed. The thickness measuring device described in 1. The thickness calculation unit calculates the thickness of the paper by averaging the values of the period during which the output of the thickness detection unit is stable among the displacement amounts of the thickness detection roller detected by the thickness detection unit. The thickness measuring apparatus according to claim 2. A paper detection unit that is provided on the upstream side of the conveyance path from the thickness detection unit and detects the paper,
In addition,
The thickness measurement apparatus according to claim 1, wherein the energization control unit starts the energization after the sheet detection unit detects a sheet. The energization control unit acquires the conveyance speed of the paper, calculates an arrival time when the paper reaches the thickness detection roller, and is necessary for the thickness detection roller and the operation unit to contact at the arrival time. The thickness measurement apparatus according to claim 4, wherein the energization is started at a time that is equal to or greater than a necessary energization preparation time for energizing the electromagnet to be before the arrival time.

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