JP2011230883A - Paper sheet residual amount detection device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily detect paper sheet residual amounts in adjacent stacking trays with a simple configuration.SOLUTION: The stacking trays 5a, 5b are placed side by side such that the stacking trays 5a, 5b are adjacent to each other, paper sheets 7a, 7b are placed on the stacking trays 5a, 5b, and the stacking trays 5a, 5b are displaced upward by consumption thereof. Slide terminal parts 17a, 17b are projected to the other stacking tray 5a, 5b directions from the adjacent stacking trays 5a, 5b, and are slidingly displaced according to the stacking trays 5a, 5b. A position detection part 19 has electrode patterns DIG0-GND on which the slide terminal parts 17a, 17b slidably abut, on respective counter faces of an insulation board 21 disposed in a displacement range of the slide terminal parts 17a, 17b between the stacking trays 5a, 5b. The position detection part 19 obtains position detection signals corresponding to abutment positions of the slide terminal parts 17a, 17b from the electrode patterns DIG0-GND.

Description

  The present invention relates to a sheet remaining amount detection device and an image forming apparatus, and is suitable for mounting on an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction peripheral (MFP) having these functions. The present invention relates to an improvement in a quantity detection device and the image forming apparatus.

  Conventionally, an image forming apparatus forms a latent image on the surface of a rotating photoconductor based on optically read image data, forms a toner image from the latent image with toner, and feeds it from a built-in paper feeding device. A configuration is well known in which a toner image is transferred from a rotating photosensitive member to a sheet, the sheet is heated and fixed through a heat fixing unit, and discharged.

  In order to enable a large amount of printing in the image forming apparatus, for example, a stacking tray on which about 1500 sheets of paper can be placed side by side, and when the paper on one stacking tray is consumed, the other stacking Controls switching of the paper feed rollers, etc., so that the paper on the tray is fed, and controls switching of the paper feed rollers, etc., so that when the paper on the other stacking tray is exhausted, the paper on the other stacking tray is fed again. A configuration has been proposed.

  In such a configuration, if paper is alternately supplied to the stacking tray where the paper has been consumed, a large amount of continuous printing is possible. Therefore, in order to ensure smooth large-scale printing, the paper is detected based on the position detection of the stacking tray. It is important to know the remaining amount and replenish it.

  Conventionally, in this type of paper feeder A, as shown in FIG. 7, lift trays 3a and 3b that move up and down by a motor drive are arranged on the inner bottom of the unit case 1, and the stacking trays 5a and 5b are individually mounted. As the sheets 7a and 7b set on the stacking trays 5a and 5b are consumed by feeding, the stacking trays 5a and 5b are moved up and displaced by the lift portions 3a and 3b, and the positions of these displacements are detected. A configuration for detecting by the device B is known.

  For example, as shown in FIGS. 8A and 8B, the remaining amount position detection device B has a support column 9 disposed in the vicinity of the stacking tray 5a, and a recess extending in the vertical direction on the surface of the support column 9 facing the stacking tray 5a. A groove 11a is provided, and opposed pairs of the light emitting element 13a and the light receiving element 13b are dispersedly arranged in three upper and lower positions in the concave groove 11a, while the shielding plate 15a protrudes from the stacking tray 5a and is loosely inserted into the concave groove 11a. Is formed.

  FIG. 8B shows, for example, only a facing pair of, for example, the uppermost light emitting element 13a and light receiving element 13b in FIG. Although FIG. 8 shows only the remaining position detection device B on the loading tray 5a side, the remaining position detection device B near the loading tray 5b has the same configuration.

  For this reason, an on / off signal obtained by independently blocking light between any of the light-emitting elements 13a and the light-receiving elements 13b by the shielding plate 15a by the stacking tray 5a that rises and displaces as the sheet 7a is consumed due to the sheet feeding is illustrated. Output to the processing circuit that does not, and based on this, the position of the stacking tray 5a is individually detected to grasp the remaining amount of paper.

  Incidentally, as a conventional publication for setting a large amount of sheets in an image forming apparatus, for example, a sheet feeding apparatus disclosed in Japanese Patent Laid-Open No. 2001-261167 (Patent Document 1) has been proposed.

  This patent document 1 is a paper feeding device of an image forming / reading device, and has a configuration capable of feeding a large capacity and two types of paper, and capable of feeding a large capacity, and two types. It can be supplied, and wasteful space is hardly generated.

  As a conventional publication for detecting the remaining amount of paper in an image forming apparatus, for example, a remaining paper quantity detection method disclosed in Japanese Patent Laid-Open No. 2001-302018 (Patent Document 2) has been proposed.

  In Patent Document 2, the upper limit position detection means detects whether or not the upper surface of the paper placed on the lift base is at the upper limit position prior to the lift of the lift base in the paper feed tray by the lift means. Whether the platform is at the lower limit position or not is detected by the lower limit position detection means, and whether or not the lifting platform before the elevation is at the lower limit position is detected, the rising time measured by the rising time measuring means or the storage means Based on the remaining amount of paper stored in the paper tray, the remaining amount of paper placed on the lifting platform is newly calculated, and the remaining amount of paper placed on the lifting platform in the paper feed tray is determined. It detects correctly.

JP 2001-261167 A JP 2001-302018 A

  However, in the conventional paper remaining amount detection apparatus B shown in FIG. 8 described above, a plurality of pairs of light emitting elements 13a and light receiving elements 13b are arranged on the support pillars 9 arranged close to the individual stacking trays 5a and 5b. This is necessary, and the arrangement and assembly of the light emitting and light receiving elements 13a and 13b are troublesome, and the cost is likely to increase.

  Further, Patent Document 1 has a configuration that can feed two types of paper, and only discloses that the remaining amount of paper is detected by the remaining amount sensor, and discloses a specific method for detecting the remaining amount of paper. is not.

  Further, in Patent Document 2, the intermediate position between the upper limit and the lower limit position is the detected upper limit and lower limit position and the rising time measured by the rising time measuring means or the remaining amount of paper stored in the storage means. Since the detection is performed indirectly based on the calculation, the detection configuration is complicated, the intermediate position is not directly detected accurately, and there is room for improvement.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a remaining paper amount detecting device and an image forming apparatus that can easily detect the remaining amount of paper in adjacent stacking trays with a simple configuration. .

  In order to solve such a problem, a remaining paper amount detection device according to claim 1 of the present invention is a stacking tray on which paper is placed and whose displacement is controlled upward by the consumption of the paper, so that they are adjacent to each other. The displacement range of the slide terminal section between a plurality of stacking trays juxtaposed to each other, a slide terminal section projecting from the adjacent stacking tray toward the other stacking tray and slidingly displaced according to the stacking tray, and the stacking tray facing each other An electrode pattern in which a sliding terminal portion facing the insulating substrate disposed on each of the opposing surfaces is slidably contacted, and a position corresponding to a contact position of the sliding terminal portion to which a predetermined potential is applied And a position detection unit on which an electrode pattern for obtaining a detection signal is formed.

  In the sheet remaining amount detecting apparatus according to claim 2 of the present invention, the position detecting unit forms a plurality of electrode patterns on each of the opposing surfaces of the insulating substrate, each of which has a different displacement range direction. And it is the structure which obtains the signal according to the short circuit between the electrode patterns for every section by the slide terminal part, and the open combination as a position detection signal.

  According to a third aspect of the present invention, there is provided a sheet remaining amount detecting device, wherein the position detecting unit is formed in common in the remaining sections except for one section among a plurality of sections on each facing surface of the insulating substrate. And an electrode pattern different for each portion, and a signal corresponding to a short-circuit combination of the short-circuit pattern and the electrode pattern for each section by the slide terminal portion is obtained as the position detection signal.

  According to a fourth aspect of the present invention, there is provided the remaining sheet quantity detecting device, wherein the position detecting unit is configured such that the one section removed is a section at one end of a plurality of sections.

  In the sheet remaining amount detecting apparatus according to claim 5 of the present invention, the position detecting unit has a resistance pattern formed in the displacement range direction and a short-circuit pattern along the resistance pattern on each facing surface of the insulating substrate. The position detection signal is obtained from a circuit formed by a short circuit between the resistance pattern and the short circuit pattern by the slide terminal portion.

  According to a sixth aspect of the present invention, there is provided an image forming apparatus for forming an image on a paper fed from a paper remaining amount detecting device according to any one of the first to fifth aspects and a paper feeding device having the paper remaining amount detecting device. And an image forming unit that forms an image of data.

  In the sheet remaining amount detecting apparatus according to the first aspect of the present invention, the stacking tray on which the sheets are stacked is displaced upward by the consumption of the sheets, so that the slide terminal unit moves on the electrode pattern of the position detecting unit. Since the position detection signal is obtained from the position detection unit according to the slide displacement and the contact position of the slide terminal unit, it is easy to detect the remaining amount of paper in each adjacent stacking tray using a common detection member, and the configuration Simple.

  In the sheet remaining amount detecting device according to the second aspect of the present invention, a plurality of electrode patterns different for each section are formed on each facing surface of the insulating substrate, and a short circuit between the electrode patterns for each section by the slide terminal portion. Since a signal corresponding to the combination of opening is obtained as a position detection signal, the remaining amount of paper can be detected stepwise.

  In the sheet remaining amount detecting device according to the third aspect of the present invention, the short-circuit pattern that is commonly formed in the remaining sections except for one section among the plurality of sections on each facing surface of the insulating substrate, and for each of the positions. Since a signal corresponding to the short-circuit combination of the short-circuit pattern and the electrode pattern for each section by the slide terminal portion is obtained as the position detection signal, the paper remaining step by step with a simpler configuration. The quantity can be detected.

  In the sheet remaining amount detecting apparatus according to the fourth aspect of the present invention, since the one section removed in the position detection unit is the section at one end of the plurality of sections, the configuration is further simplified.

  In the sheet remaining amount detecting device according to claim 5 of the present invention, the position detecting unit has a resistance pattern formed in the displacement range direction and a short circuit pattern along the resistance pattern on each facing surface of the insulating substrate. Since the position detection signal is obtained from a circuit formed by short-circuiting the resistance pattern and the short-circuit pattern by the slide terminal portion, it is possible to detect the remaining amount of paper continuously with a simple configuration.

1 is a schematic configuration diagram showing an embodiment of a paper feeding device including a remaining paper amount detecting device according to the present invention. It is a principal part top view which shows the paper remaining amount detection apparatus which concerns on this invention. It is a chart explaining operation | movement of the paper remaining amount detection apparatus which concerns on this invention. 1 is an internal configuration diagram illustrating an internal configuration of an image forming apparatus according to an embodiment of the present invention that is equipped with a remaining paper amount detection device according to an embodiment of the present invention. It is a figure explaining the operation panel part of FIG. It is a figure explaining the other example of the paper remaining amount detection apparatus of this invention. It is a schematic block diagram which shows the conventional paper feeder. It is the schematic longitudinal cross-sectional view (FIG. 8A) and horizontal cross-sectional view (FIG. 8B) which show the residual amount position detection apparatus in FIG.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a remaining paper amount detecting device and an image forming apparatus according to the present invention will be described below with reference to the drawings.

  The sheet remaining amount detection apparatus according to the present invention will be described together with a sheet feeding apparatus having the same, and the same reference numerals are given to the same parts as those in the conventional configuration.

  FIG. 1 is a schematic configuration diagram showing an embodiment of a remaining sheet detecting device according to the present invention together with a sheet feeding device A.

  In FIG. 1, a pair of lift portions 3a and 3b that move up and down by a motor drive, for example, are juxtaposed on the inner bottom of a unit case 1 having a box shape with an open top. Loading trays 5a and 5b on which 7a and 7b are set are placed and fixed on each.

  The lift sections 3a and 3b move and displace the stacking trays 5a and 5b by a motor (not shown) that is driven and controlled as the sheets 7a and 7b set on the stacking trays 5a and 5b are consumed. Has a function of moving down.

  The stacking trays 5a and 5b are regulated so that the uppermost portions of the sheets 7a and 7b are always positioned at the sheet feeding position that is the upper open position of the unit case 1, and accompanying the consumption of the sheets 7a and 7b due to sheet feeding Will move up.

  The following remaining sheet detecting device B is formed for detecting the remaining sheet as the stacking trays 5a and 5b move upward.

  The remaining sheet detecting device B includes a displacement range of the slide terminal portions 17a and 17b between the adjacent stacking trays 5a and 5b, the slide terminal portions 17a and 17b protruding from the adjacent stacking trays 5a and 5b. An electrode pattern to be described later in which slide terminal portions 17a and 17b facing the respective opposing surfaces of the insulating substrate 21a arranged in a slidable manner are slidably contacted, and a predetermined potential is applied to the slide terminal portions 17a and 17b. And a position detector 19 on which an electrode pattern for obtaining a position detection signal corresponding to the contact position of 17b is formed. Details of the electrode pattern will be described later.

  The slide terminal portions 17a and 17b have U-shaped curved conductive leaf springs, and cantilevered on the side of the stacking trays 5a and 5b so as to project toward the adjacent stacking trays 5a and 5b. The leading end is elastically brought into contact with the opposing surface of the insulating substrate 21 and is slid on the insulating substrate 21 by the vertical displacement of the stacking trays 5a and 5b.

  The insulating substrate 21 has a length in the vertical direction which is slightly longer than the vertical displacement range of the adjacent stacking trays 5a and 5b, that is, the vertical displacement range of the slide terminal portions 17a and 17b. Electrode patterns DIG0, DIG1, DIG2, and GND as shown in FIG. 2 are formed on both opposing surfaces to form the position detection unit 19 described above.

  Since the insulating substrate 21 is a common member of the adjacent stacking trays 5a and 5b and the electrode patterns DIG0 to GND on both opposing surfaces are the same, only one side will be described below and the electrode patterns on the opposing surface will be described and illustrated. Omitted.

  That is, the vertical direction of the insulating substrate 21 is divided into eight equal sections D1, D2, D3, D4, D5, D6, D7, and D8, and each section D1 to D8 includes a plurality of sections extending in the vertical (longitudinal) direction. The electrode patterns DIG0, DIG1, DIG2, and GND are formed, and the presence / absence and width shape of the electrode patterns DIG0 to GND in the individual sections D1 to D8 are different. The electrode patterns DIG0 to GND are formed by a known printing method or the like.

  The electrode patterns DIG0 to GND are external connection portions P0, P1, P2, and P3 at the lower end portion of the insulating substrate 21, and the electrode patterns DIG0, DIG1, GND, and DIG2 are sequentially arranged from the left side of the insulating substrate 21 in the drawing. Although not shown, a predetermined direct current voltage (for example, +3 V, “1” potential) is applied to the electrode patterns DIG0 to DIG2 from the external connection portions P0 to P2, although not shown, and the electrode pattern GND is formed. The external connection portion P3 is connected to ground (“0” potential).

  That is, the electrode pattern DIG0 is formed in an elongated unit band shape from the lower end portion of the insulating substrate 21 and extends upward in the section D1, and extends upward in a double width over the sections D2 to D5 and is open at the tip.

  The electrode pattern DIG1 formed on the right side of the electrode pattern DIG0 has a unit band shape in the sections D4 and D5 and doubles in the sections D6 to D8 up to the upper end portion (section D8) of the insulating substrate 21 on the extension line of the electrode pattern DIG0. The right end extends in a unit band shape to the lower end so as to surround the electrode patterns GND and DIG2.

  On the right side of the electrode pattern DIG1, an electrode pattern GND formed in a unit band shape extends upward from the lower end of the insulating substrate 21 to the section D1 to the section D7 in an elongated unit band shape and is opened.

  On the right side of the electrode pattern GND, the electrode pattern DIG2 extends from the lower end portion of the insulating substrate 21 upward in a double width from the section D1 to the section D2, extends upward in the unit band shape to the sections D3 and D4, and sections D5 to D6. It is extended and opened again with a double width.

  The electrode pattern GND is formed in common in the remaining sections excluding the upper one section D8 among the plurality of sections D1 to D8, and functions as a short-circuit pattern for short-circuiting the electrode patterns DIG0 to DIG2 as described later.

  The slide terminal portion 17a traverses the electrode pattern (short circuit pattern) GND in the process of being vertically slid in the state of being in electrical contact with the electrode patterns DIG0 to DIG2 and GND on the insulating substrate 21, and the electrode pattern DIG0. In DIG2, the double width portion and the electrode pattern GND are short-circuited, and the external connection portions P0 to P2 of the short-circuited electrode patterns DIG0 to DIG2 have a function of “0” potential.

  The external connection portions P0 to P2 of the electrode patterns DIG0 to DIG2 that are not short-circuited to the electrode pattern GND remain at “1” potential.

  When the slide terminal portion 17a is slid vertically on the insulating substrate 21, in the sections D1 to D7, the form in which the electrode patterns DIG0 to DIG2 are short-circuited with the electrode pattern GND changes, and the outside of the electrode patterns DIG0 to DIG2 The connecting portions P0 to P2 change to “0” potential.

  FIG. 3 is a diagram illustrating a combination state of the potentials “1” and “0” of the electrode patterns DIG0 to DIG2 in the sections D1 to D8 in the position detection unit 19, and the sections D1 to D8 according to these combination states. And a position detection signal is output from a processing circuit (not shown).

  For example, in the section D8 from 0% to 12.5%, the electrode patterns DIG0 to DIG2 are “1, 1, 1”, and in the section D7 from 12.5% to 25%, the electrode patterns DIG0 to DIG2 are “1, In the section D1 from 87.5% to 100%, the electrode patterns DIG0 to DIG2 become “1, 1, 0”, and the combination of the “1” potential and the “0” potential of the electrode patterns DIG0 to DIG2 Since the position of the slide terminal portion 17a (loading tray 5a) is specified by this, it can be used for detecting the remaining amount of paper.

  Next, the operation of the above-described remaining paper amount detection device B will be briefly described. In the following description, it is assumed that the sheet 7a starts to be fed from the stacking tray 5a.

  When 100% of the sheets 7a and 7b are set on the stacking trays 5a and 5b, the stacking trays 5a and 5b are positioned at the bottom and the slide terminal portion 17a contacts the lower part of the section D1 on the insulating substrate 21, and only the electrode pattern DIG2 is provided. Is short-circuited to the electrode pattern (short-circuit pattern) GND, and the electrode patterns DIG0 to DIG2 become “1, 1, 0”.

  Therefore, it is possible to obtain a position detection signal indicating 100% by the processing circuit for the stacking trays 5a and 5b.

  When the sheet 7a is consumed, the stacking tray 5a rises according to the amount of consumption, and the slide terminal portion 17a slides upward on the insulating substrate 21. When reaching the section D5, the electrode pattern DIG0 is reached. ˜DIG2 is short-circuited to the electrode pattern (short circuit pattern) GND, and the electrode patterns DIG0 to DIG2 are “0, 0, 0”. Therefore, it is possible to obtain a position detection signal indicating 50% for the stacking tray 5a.

  Further, when the sheet 7a is consumed and the stacking tray 5a is raised to the top and the slide terminal portion 17a reaches the section D8, the electrode patterns DIG0 to DIG2 are not short-circuited with the electrode pattern (short circuit pattern) GND. The patterns DIG0 to DIG2 are “1, 1, 1”.

  Therefore, it is possible to obtain a position detection signal indicating 0% with respect to the stacking tray 5a.

  For this reason, if switching to paper feed control of the paper 7b from the stacking tray 5b is performed by appropriate means, paper feed of the paper 7b from the stacking tray 5b is started. If paper 7a is replenished to the stacking tray 5a, it is possible to prepare for the next paper feed.

  Next, an embodiment of an image forming apparatus C equipped with the above-described paper feeding device A and paper remaining amount detection device B will be described with reference to FIG.

  In FIG. 4, the image forming apparatus C includes an image capturing unit 25, a storage unit 27, an operation panel unit 29, a communication unit 31, and a printing unit 33 with the main control unit 23 as a center. ing. The image forming apparatus C has a configuration other than this, but since it is not the gist of the present invention, description and illustration are omitted.

  For example, as shown in FIG. 4, the image reading unit 25 is disposed on the upper part of the main body case 35 of the image forming apparatus C, and optically reads an image from, for example, a printed document under the control of the main control unit 23. This is an image data input unit such as a known scanner that generates an electronic print job by performing filter processing or the like, and the generated print job is sequentially stored in the storage unit 27.

  The storage unit 27 is a readable / writable hard disk that stores read image data from the image reading unit 25 or received image data from the communication unit 31 and an operation program of the main control unit 23 under the control of the main control unit 23. .

  The operation panel unit 29 is arranged on the upper part of the main body case 35, and is controlled by the main control unit 23. By pressing a key on which an image related to the above is displayed, it has a function as an input unit for accepting image reading, printing instructions, and other instructions.

  That is, for example, as shown in FIG. 5, the operation panel unit 29 selects various operation instructions and selection keys 29a for printing (printing, copying) processing, printer processing, scanner processing, fax processing, etc. A numeric keypad 29b, a start key 29c, a display panel unit 29d, and the like are provided as input units for inputting settings, changes, and the like of the operation functions.

  The display panel unit 29d functions as a display unit that displays the operation of the image forming apparatus C and displays the remaining amount of paper with the bar display 29e based on the position detection signal from the position detection unit 19 described above.

  The communication unit 31 in FIG. 4 is an interface unit that transmits and receives image data to and from an information processing apparatus (computer) via a network (not shown) according to a predetermined protocol under the control of the main control unit 23. is there.

  The printing unit 33 develops and generates print image image data from the image data, forms a toner image based on the image data, transfers the toner image onto a sheet, and discharges it.

  That is, the printing unit 33 develops toner on the photosensitive drum with toner based on the print image image data and the above-described paper supply device A having the paper remaining amount detection device B disposed in the main body case 35, and outputs it to the paper. A transfer unit 37 serving as an image forming unit to be transferred to the image forming unit, a fixing unit 39 for fixing the sheet on which the toner image is transferred, and a reverse conveying unit 25 for returning the fixed sheet to the transfer unit 19 for duplex printing. These form the printing section 33. Reference numeral 41 denotes a paper discharge tray.

  The main control unit 23 includes a CPU, a ROM that stores an operation program for the CPU, and a working RAM (none of which are shown). The main control unit 23 is configured as described above, and includes the image reading unit 25, the storage unit 27, and the user. It has a function of controlling the history creating unit 7, the operation panel unit 29, the printing unit 33, the communication unit 31, and the like.

  The main control unit 23 has a function of forming paper remaining amount data based on the position detection signal from the processing circuit described above and controlling the display on the display panel unit 29d of the operation panel unit 29.

  As described above, the sheet remaining amount detecting device B of the present invention is the stacking trays 5a and 5b on which the sheets 7a and 7b are placed and controlled to be displaced upward by the consumption of the sheets 7a and 7b, and are adjacent to each other. A plurality of juxtaposed stacking trays 5a, 5b, slide terminal portions 17a, 17b projecting from adjacent stacking trays 5a, 5b in the direction of the other stacking trays 5a, 5b and slidingly displaced according to the stacking trays 5a, 5b; Between the facing stacking trays 5a and 5b, the sliding terminal portions 17a and 17b facing each other are slidably brought into contact with the opposing surfaces of the insulating substrate 21 arranged in the displacement range of the sliding terminal portions 17a and 17b. Electrode patterns DIG0 to GND, which are applied with a predetermined potential and obtain position detection signals corresponding to the contact positions of the slide terminal portions 17a and 17b. It is provided with a position detector 19 over emissions DIG0~GND is formed.

  In addition, the position detection unit 19 forms a plurality of electrode patterns DIG0 to GND in which the displacement range direction is divided into a plurality of sections divided on each facing surface of the insulating substrate 21, and one of the plurality of sections is formed. An electrode pattern (short-circuit pattern) GND that is commonly formed in the remaining sections except for one section at the end, and electrode patterns DIG0 to DIG2 that are different for each of the sections, and a section by the slide terminal portions 17a and 17b Each electrode pattern (short-circuit pattern) GND and a signal corresponding to a short-circuit combination of the electrode patterns DIG0 to DIG2 are formed as position detection signals.

  Therefore, the remaining amount of the sheets 7a and 7b can be detected only by elastically contacting the slide terminal portions 17a and 17b provided on the adjacent paper stacking trays 5a and 5b with the insulating substrate 21, or simply adjacent to each other. The electrode patterns DIG0 to GND are formed on the shared insulating substrate 21 between the stacking trays 5a and 5b, and the sheets of the adjacent stacking trays 5a and 5b are simply brought into contact with the slide terminal portions 17a and 17b from the opposing surface. Since the remaining amount of 7a and 7b can be detected, the configuration and assembly are extremely simple and inexpensive.

  By the way, in the remaining paper amount detection apparatus B of the present invention, the electrode pattern (short circuit pattern) GND is configured to be removed only in the upper end section D8, but a configuration in which it is removed in any section is also possible. In the configuration in which the one section is one end section, the electrode pattern (short-circuit pattern) GND can be formed short, and the shape can be easily reduced in size.

  Further, in the remaining sheet amount detecting device B of the present invention, a plurality of electrode patterns DIG0 to GND are formed in each section in which the displacement range direction is divided into a plurality of sections, and each section is formed by the slide terminal portions 17a and 17b. If a signal corresponding to a combination of short circuit and open circuit between the electrode patterns DIG0 to GND is obtained as a position detection signal, the remaining amount of paper in the adjacent stacking trays 5a and 5b can be easily detected with a simple configuration.

  In short, the slide terminal portions 17a, 17b facing each other are slidable on the opposing surfaces of the insulating substrate 21 arranged in the displacement range of the slide terminal portions 17a, 17b between the facing trays 5a, 5b. A position detection unit 19 in which electrode patterns DIG0 to GND are formed, which are electrode patterns DIG0 to GND to be contacted, and to which a predetermined potential is applied to obtain position detection signals corresponding to the contact positions of the slide terminal portions 17a and 17b. If so, the object of the present invention can be achieved.

  In the paper remaining amount detection apparatus B of the present invention described above, the slide displacement range of the stacking trays 5a and 5b is divided into a plurality of sections D1 to D8, and the same sheet remaining amount is gradually increased (digitally) in each of the sections D1 to D8. However, the present invention is not limited to this.

  For example, as shown in FIG. 6, on the opposing surface of the insulating substrate 21 described above, an elongated strip-like high-resistance electrode pattern (resistance pattern) DIG3 and an electrode pattern (short circuit) formed in parallel with a slight gap therebetween. Pattern) GND, and the position detection signal is continuously transmitted from the external connection portion P4 formed by short-circuiting the electrode pattern (resistance pattern) DIG3 and the electrode pattern (short-circuit pattern) GND by the slide terminal portions 17a and 17b ( A configuration in which the position detecting unit 19 for detecting in an analog manner is also possible.

  In such a configuration, when the slide terminal portions 17a and 17b slide and displace due to the slide displacement of the loading trays 5a and 5b, the position of the resistance pattern DIG3 that is short-circuited by the electrode pattern (short-circuit pattern) GND changes, and the electrode pattern ( Since the circuit resistance corresponding to the electrode pattern (short-circuit pattern) GND changes from the resistance pattern DIG3, based on this, the remaining amount of sheets 7a and 7b can be detected from the displacement position of the stacking trays 5a and 5b.

  In addition, the remaining paper amount detection device B of the present invention is not limited to the configuration having the two stacking trays 5a and 5b, but can be implemented in a configuration in which a plurality of stacking trays 5a and 5b are adjacent to each other.

  Furthermore, in each of the electrode patterns DIG0 to DIG2 described above, some of the sections D2 to D5 are twice as wide as the other sections, but the present invention is not limited to double width. However, it is preferable to form partly wide from the viewpoint of ensuring reliable contact.

  Furthermore, the stacking trays 5a and 5b are not limited to the configuration in which the vertical displacement is controlled by the lift portions 3a and 3b that are moved up and down by the motor drive, and may be configured to be biased and displaced upward. The object of the present invention can be achieved as long as the stacked tray is displaced upward by the consumption of the paper.

  The image forming apparatus C equipped with the remaining paper amount detection device of the present invention has the same effect as the remaining paper amount detection device.

1 Unit case 3a, 3b Lift part 5a, 5b Loading tray 7a, 7b Paper 9 Support pillar 11a, 11b Groove 13a Light emitting element 13b Light receiving element 15a, 15b Shield plate 17a, 17b Slide terminal part 19 Position detection part 21 Insulating substrate 23 Main control section 25 Image capture section 27 Storage section 29 Operation panel section 29a Select key 29b Numeric keypad 29c Start key 29d Display panel section 31 Communication section 33 Printing section 35 Main body case 37 Transfer section 39 Fixing section 41 Paper discharge tray A Paper feed device B Remaining position detection device C Image forming device DIG0, DIG1, DIG2 Electrode pattern DIG3 Electrode pattern (resistance pattern)
GND electrode pattern (short circuit pattern)
P0, P1, P2, P3, P4 External connections

Claims (6)

A plurality of stacking trays on which paper is placed and whose displacement is controlled upward by consumption of the paper, and are juxtaposed to be adjacent to each other;
A slide terminal portion projecting from the adjacent stacking tray toward the other stacking tray and slidingly displaced according to the stacking tray;
It is an electrode pattern in which the slide terminal portion facing this is slidably abutted on each opposing surface of the insulating substrate disposed in the displacement range of the slide terminal portion between the loading trays facing each other, A position detection unit formed with the electrode pattern to obtain a position detection signal according to a contact position of the slide terminal unit to which a predetermined potential is applied;
A sheet remaining amount detecting apparatus comprising:   The position detection unit forms a plurality of the electrode patterns different for each section obtained by dividing the displacement range direction into a plurality of sections on each facing surface of the insulating substrate, and the slide terminal unit for each section 2. The sheet remaining amount detecting device according to claim 1, wherein a signal corresponding to a combination of short circuit and open between electrode patterns is obtained as the position detection signal.   The position detection unit includes, on each facing surface of the insulating substrate, a short circuit pattern that is commonly formed in the remaining sections except for one section among the plurality of sections, and the electrode patterns that are different for each of the sections. The sheet remaining amount detection apparatus according to claim 2, wherein a signal corresponding to a short-circuit combination of the short-circuit pattern and the electrode pattern for each section by the slide terminal unit is obtained as the position detection signal.   The sheet remaining amount detection device according to claim 3, wherein the position detection unit is a section at one end of the plurality of sections, the removed one section.   The position detection unit has a resistance pattern formed in the direction of the displacement range and a short circuit pattern along the resistance pattern on each facing surface of the insulating substrate, and the resistance pattern by the slide terminal unit and the short circuit pattern The sheet remaining amount detection apparatus according to claim 1, wherein the position detection signal is obtained from a circuit formed by a short circuit.   6. A sheet remaining amount detecting device according to claim 1, and an image forming unit for forming image data on the sheet fed from a sheet feeding device having the sheet remaining amount detecting device. An image forming apparatus.

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