Developer storage height detection device, developer supply device and image forming device

Abstract

A developer storage height detection device, a supply device, and an image forming device are provided. The device comprises: a main body provided with a conveying path for conveying developer; a developer conveying unit rotating within the conveying path and having a spiral conveying portion; a swinging unit in contact with the developer surface conveyed within the conveying path and swinging at least in accordance with the height of the developer surface; a detection unit detecting the swinging state of the swinging unit; and a discrimination unit discriminating the presence or absence of developer based on a detection signal output from the detection unit. The conveying unit comprises a non-conveying portion having no conveying portion and an eccentric shaft as its rotating shaft; the swinging unit is configured to swing in the non-conveying portion; and the discrimination unit samples the detection signal at intervals obtained by dividing the time required for the conveying unit to rotate once by a predetermined number. When the ratio of the detection signal below the output level indicating a relatively low storage height within the required time is greater than a threshold value, the discrimination unit outputs a signal discriminating the absence of developer.

Description

Technical Field

[0001] The present disclosure relates to a developer storage level detection device, a developer supply device, and an image forming apparatus. Background Art

[0002] Conventionally, as a technique for detecting the height of the developer surface (storage height) in which developer is stored, for example, the techniques described in the following Patent Documents 1 and 2 are known.

[0003] Japanese Patent Publication No. 2016-151634 describes the following technology: in a sub-hopper (colorant storage portion), a floating member for detecting the upper surface level of the colorant is arranged to swing freely around an axis, and on the other hand, a light shielding plate is provided, which is mounted on the axis and swings up and down with the swing of the floating member and is detected by a transmission type light sensor, wherein the sub-hopper is arranged below a colorant bottle that is assembled in a detachable manner, accommodates the developer supplied from the colorant bottle, and supplies the accommodated developer to the developer by driving a supply roller.

[0004] Patent Document 1 also describes a floating member that swings up and down via a cam that rotates with a stirring shaft positioned below it. This oscillation prevents the floating member from colliding with a stirring plate, which is mounted on the stirring shaft and is used to even out the toner's upper surface, even if the toner in the sub-hopper becomes low. Patent Document 1 also describes a transmissive optical sensor that detects, via a light shielding plate, the downward swing of the floating member caused by the toner in the sub-hopper becoming low. If this detection frequency falls below a predetermined number, the toner is determined to be nearing exhaustion.

[0005] Japanese Patent Application Laid-Open No. 2016-48359 describes a technique for detecting the amount of toner having substantially the same configuration as that of the technique described in Japanese Patent Application Laid-Open No. 2016-151634 except for the light shielding plate and the transmissive photosensor.

[0006] In addition, the following content is recorded in the Japanese Patent Gazette No. 2016-48359: A magnet is provided on the upper surface of the free end side of the floating member that swings toward the upper limit in the sub-hopper, and an empty sensor that works according to the position of the above-mentioned magnet is installed on the outer side surface of the sub-hopper. The empty sensor detects the state in which the colorant in the sub-hopper becomes less and the floating member swings downward via the magnet. When this state is detected, it is determined that the colorant is insufficient. Summary of the Invention

[0007] The present disclosure provides a developer storage height detection device and a developer supply device and an image forming device using the same. The device can reliably detect the storage height of the developer in a conveying path, compared with a case where the device is not configured as follows, wherein a developer conveying unit configured to have a spiral conveying portion rotates in the conveying path, and the above-mentioned structure is as follows: the conveying unit has a non-conveying portion, the swinging unit is configured to swing in the non-conveying portion, the discrimination unit samples the detection signal at an interval obtained by dividing the time required for the conveying unit to rotate one circle by a predetermined number, and discriminates that there is no developer when the ratio of the detection signal below the output level determined to be relatively low in the required time is greater than a threshold value.

[0008] According to a first aspect of the present disclosure, a developer storage height detection device is provided, wherein the developer storage height detection device includes: a main body provided with a conveying path for conveying developer; a developer conveying unit configured to rotate within the conveying path and having a conveying portion spirally provided around a rotating shaft; a swinging unit that contacts a developer surface of the developer conveyed within the conveying path and swings at least in accordance with the height of the developer surface; a detection unit that detects a swinging state of the swinging unit; and a determination unit that determines the presence or absence of developer based on a detection signal output from the detection unit, wherein the conveying unit has a non-conveying portion that does not have the conveying portion, and the rotating shaft is configured as an eccentric shaft with an axial center offset, the swinging unit is configured to swing in the non-conveying portion, and the determination unit samples the detection signal at intervals obtained by dividing a time required for the conveying unit to rotate once by a predetermined number, and outputs a signal for determining that the developer is absent when a ratio of the detection signal that is below an output level indicating that the storage height is relatively low within the required time is equal to or greater than a threshold value.

[0009] According to the second aspect of the present disclosure, the swing unit includes a detection portion that swings in conjunction with the swing unit, and the detection unit is configured by a unit that detects the detection portion by transmitting or blocking light.

[0010] According to the third aspect of the present disclosure, the swing unit is provided with a light-reflective detection unit that swings in conjunction with the swing unit, and the detection unit is configured to detect the detection unit by detecting the presence or absence of light reflection.

[0011] According to the fourth aspect of the present disclosure, the swing unit is provided with a light-reflective detection unit that swings in conjunction with the swing unit, and the detection unit is configured to detect the detection unit by a difference in the amount of reflected light.

[0012] According to a fifth aspect of the present disclosure, the detection unit includes two or more detection sections for detecting transmission or interruption of the light.

[0013] According to a sixth aspect of the present disclosure, the detection unit includes two or more detection sections for detecting the presence or absence of reflection of the light.

[0014] According to the seventh aspect of the present disclosure, a measuring unit is provided that measures the humidity near the main body, and the determining unit has a function of changing the threshold value according to the difference in humidity measured by the measuring unit.

[0015] According to the 8th scheme of the present disclosure, a developer supply device is provided, wherein the developer supply device comprises: a main body, which has a receiving port for receiving the developer supplied from the developer container, a conveying path for conveying the developer, and a delivery port for delivering the developer in the conveying path to a supply destination; a developer conveying unit, which is configured to rotate in the conveying path and has a conveying portion spirally arranged around a rotating shaft; a delivery unit, which delivers the developer in the conveying path to the delivery port; and a storage height detection device, which detects the storage height of the developer surface conveyed in the conveying path, and the storage height detection device is composed of the developer storage height detection device described in any one of claims 1 to 7.

[0016] According to the ninth aspect of the present disclosure, the level determined as the low storage height is a level at which the amount of developer delivered to the delivery outlet by the delivery unit does not fall below a predetermined minimum limit amount.

[0017] According to the 10th scheme of the present disclosure, the developer container has a feeding unit, which is driven to convey the developer toward the receiving port when receiving the signal output from the discrimination unit that there is no developer. The level determined as the low storage height is the level at which the remaining amount of developer contained in the developer container does not exceed a predetermined target remaining amount.

[0018] Furthermore, according to an eleventh aspect of the present disclosure, there is provided an image forming apparatus including the developer storage level detection device described above.

[0019] According to a twelfth aspect of the present disclosure, there is provided an image forming apparatus including the developer supply device described above.

[0020] Effects of the Invention

[0021] According to the first scheme, the storage height of the developer located in the transport path can be reliably detected compared to a case where the following structure is not configured, in which a transport unit for the developer configured to have a spiral transport portion rotates, the transport unit has a non-transporting portion, the swing unit is configured to swing in the non-transporting portion, the discrimination unit samples the detection signal at intervals obtained by dividing the time required for the transport unit to rotate one circle by a predetermined number, and when the ratio of the detection signal below the output level determined to be relatively low for the required time is greater than a threshold value within the required time, it is discriminated that there is no developer.

[0022] According to the second aspect, the storage height of the developer in the conveying path can be detected more easily than when the detection unit is not configured by a unit that detects the detected portion of the swing unit by transmitting or blocking light.

[0023] According to the third aspect, compared with a case where the detection unit is not configured to detect the detected unit of the swing unit by the presence or absence of light reflection, the storage height of the developer in the conveying path can be detected while achieving space saving.

[0024] According to the fourth aspect, the difference in the storage height of the developer in the conveying path can be detected in detail compared to a case where the detection unit is not configured to detect the detected unit of the swing unit by the difference in the amount of reflected light.

[0025] According to the fifth aspect, compared with a case where the detection unit does not include two or more detection portions for detecting light transmission or light blocking, it is possible to detect differences in the storage height of the developer in the conveying path at three or more different levels.

[0026] According to the sixth aspect, compared to a case where the detection unit does not include two or more detection portions for detecting the presence or absence of light reflection, it is possible to detect differences in the storage height of the developer in the conveying path at three or more different levels.

[0027] According to the seventh aspect, the storage level of the developer in the conveying path can be accurately detected without being affected by humidity, compared to a case where the determination unit does not have a function of changing the threshold value according to the humidity measured by the measurement unit.

[0028] The developer supply device according to the eighth scheme can reliably perform detection compared to a case where the developer supply device is not configured as follows: the conveying unit has a non-conveying portion, the swinging unit is configured to exist and swing in the non-conveying portion, the discrimination unit samples the detection signal at an interval obtained by dividing the time required for the conveying unit to rotate one circle by a predetermined number, and when the ratio of the detection signal below the output level determined to be a relatively low storage height within the required time is greater than a threshold value, it is discriminated that there is no developer.

[0029] According to the ninth scheme, compared with the case where the level determined as the lower storage height is not the level at which the amount of developer delivered to the delivery outlet through the delivery unit is not less than the predetermined minimum amount, the storage height of the developer located in the conveying path can be reliably detected, and on this basis, the insufficient amount of developer delivered through the delivery unit can also be suppressed.

[0030] According to the tenth scheme, the storage height of the developer located in the conveying path can be reliably detected, and on this basis, the remaining amount of developer in the developer container can be reduced, and the developer is not wasted but effectively utilized, compared with the following situation: the developer container has a feeding unit, and when the feeding unit receives a signal output from the discrimination unit that determines that there is no developer, it is driven to convey the developer toward the receiving port, and the level determined as the low storage height is the level at which the remaining amount of developer contained in the developer container does not exceed a predetermined target amount.

[0031] According to the image forming apparatus of the eleventh aspect, the storage height of the developer in the conveying path of the main body arranged so that the developer conveying unit rotates can be reliably detected.

[0032] According to the image forming apparatus of the twelfth aspect, the storage height of the developer in the conveying path disposed in the main body of the developer supply device so as to rotate the developer conveying unit can be reliably detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram showing the overall configuration of the image forming apparatus according to Embodiment 1.

[0034] Figure 2 It shows Figure 1 A schematic diagram of a portion of the structure of an image forming apparatus.

[0035] Figure 3 It is a perspective view showing the developer supply device (with the upper panel removed) and the storage height detection device.

[0036] Figure 4 It shows Figure 3A top view of the supply device and the storage height detection device.

[0037] Figure 5 yes Figure 4 The cross-sectional schematic diagram of the replenishing device and the storage height detection device cut along the QQ line, (A) is a cross-sectional schematic diagram showing the state when the swing unit swings to the highest position, and (B) is a cross-sectional schematic diagram showing the state when the swing unit swings to the lowest position.

[0038] Figure 6 It shows Figure 3 A top view of the developer conveying unit at the storage height detection position.

[0039] Figure 7 It shows Figure 5 A cross-sectional schematic diagram of another state of the supply device and the storage height detection device.

[0040] Figure 8 1 is a conceptual diagram showing a configuration related to determination of a detection signal in a determination unit.

[0041] Figure 9 This is a conceptual diagram showing an example of the detection output of the detection unit in the first embodiment.

[0042] Figure 10 This is a schematic diagram showing an example of the configuration of the determination unit in the first embodiment.

[0043] Figure 11 This is a schematic diagram showing an example of the setting content of the detection level height of the determination unit in the first embodiment.

[0044] Figure 12 This is a plan view showing the replenishing device and storage height detection device of the second embodiment.

[0045] Figure 13 This is a schematic diagram showing another configuration example of the detection unit. DETAILED DESCRIPTION

[0046] Hereinafter, a mode for implementing the present disclosure will be described with reference to the drawings.

[0047] [Implementation Method 1]

[0048] Figure 1 and Figure 2 1 is a diagram showing an image forming apparatus 1 according to Embodiment 1 of the present disclosure. Figure 1 The overall structure of the image forming apparatus 1 is shown. Figure 2 The structure of a portion of the image forming apparatus 1 (mainly the image forming device and the developer supply device) is shown.

[0049] Figure 1 The arrows indicated by the numbers X, Y, and Z in the figures indicate the directions of width, height, and depth of the three-dimensional space assumed in the figures. In addition, in the figures, the circular mark at the intersection of the arrows in the X and Y directions indicates that the Z direction is vertically downward in the figure.

[0050] <Structure of Image Forming Apparatus>

[0051] Image forming apparatus 1 forms an image composed of toner as a developer on paper 9 as an example of a recording medium. Image forming apparatus 1 according to Embodiment 1 is configured as, for example, a printer that forms an image corresponding to image information input from an external device such as a data terminal.

[0052] like Figure 1 As shown, the image forming device 1 has a shell 10 formed with a required appearance shape, and the internal space of the shell 10 is equipped with: an image forming device 2 that forms a colorant image based on image information; an intermediate transfer device 3 that temporarily holds and conveys the colorant image formed by the image forming device 2 and then transfers it to a paper 9 for the second time; a paper feeding device 4 that receives and sends out the paper 9 to the position where the intermediate transfer device 3 is to perform the second transfer; and a fixing device 5 that fixes the colorant image after the second transfer by the intermediate transfer device 3 to the paper 9, etc.

[0053] Here, the image information is information related to images such as characters, graphics, photos, and patterns. The housing 10 is a structure formed into a desired shape by various supporting members, exterior materials, and the like. Figure 1 The dashed-dotted line with an arrow in FIG. 1 represents a main conveyance path diameter when the paper 9 is conveyed in the housing 10 .

[0054] The image forming apparatus 2 is composed of four image forming apparatuses 2Y, 2M, 2C, and 2K, each dedicated to forming a toner image of four colors: yellow (Y), magenta (M), cyan (C), and black (K).

[0055] Each of the four image forming devices 2 (Y, M, C, K) includes a photosensitive drum 21 as an example of an image holding unit that rotates in the direction indicated by arrow A. Around the photosensitive drum 21, a charging device 22, an exposure device 23, a developing device 24 (Y, M, C, K), a primary transfer device 25, a drum cleaning device 26, and other devices are arranged. Figure 1 In the figure, all of the reference numerals 21 to 26 are described only in the image forming apparatus 2K for black (K), and only a portion of the reference numerals 21 to 26 are described in the image forming apparatuses 2 (Y, M, C) for other colors.

[0056] The charging device 22 charges the outer peripheral surface (the surface on which an image can be formed) of the photosensitive drum 21 to a desired surface potential. The exposure device 23 exposes the outer peripheral surface of the photosensitive drum 21 based on image information, forming an electrostatic latent image of the desired color components (Y, M, C, K). The developing device 24 (Y, M, C, K) develops the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 21 using dry powder, or developer (toner), composed of the corresponding predetermined colors (Y, M, C, K), to form toner images of the four predetermined colors.

[0057] The primary transfer device 25 electrostatically transfers the toner images of various colors formed on the outer peripheral surface of the photosensitive drum 21 to the intermediate transfer device 3 (intermediate transfer belt 31). The drum cleaning device 26 cleans the outer peripheral surface of the photosensitive drum 21 by scraping away unnecessary toner, paper dust, and other unnecessary substances adhering to the outer peripheral surface of the photosensitive drum 21.

[0058] In these image forming devices 2 (Y, M, C, K), each location where the photosensitive drum 21 (strictly speaking, the intermediate transfer belt 31 of the intermediate transfer device 3) faces the primary transfer device 25 serves as a primary transfer position TP1 where the primary transfer of the toner image is performed.

[0059] In these four image forming devices 2Y, 2M, 2C, and 2K, for example, when an instruction for an image forming action of forming a multi-color image composed of a combination of colorant images of the above-mentioned four colors (Y, M, C, K), namely a so-called full-color image, is received, with respect to each photosensitive drum 21 rotating in the direction indicated by the arrow A in the image forming device 2 (Y, M, C, K), a charging action based on the charging device 22, an exposure action based on the exposure device 23, a developing action based on the developing device 24 (Y, M, C, K), etc. are respectively performed.

[0060] As a result, four-color toner images, each decomposed into four color components (Y, M, C, K), are independently formed on each photosensitive drum 21 in the image forming devices 2Y, 2M, 2C, and 2K. The four-color toner images formed on each photosensitive drum 21 are then transported to the primary transfer position TP1 as the photosensitive drum 21 rotates.

[0061] The intermediate transfer device 3 is a device configured to hold the toner images of the respective colors formed by the image forming devices 2 (Y, M, C, K) by primary transfer and then transport them to a position for secondary transfer onto the paper 9. The intermediate transfer device 3 is disposed below the image forming devices 2 (Y, M, C, K) within the housing 10.

[0062] The intermediate transfer device 3 also includes an intermediate transfer belt 31. This belt receives the primary transfer of toner images from the photosensitive drums 21 in the image forming devices 2 (Y, M, C, and K) and holds the toner images. The intermediate transfer belt 31 is supported by a plurality of support rollers 32a to 32f disposed inside the belt, and rotates (or circles) in the direction indicated by arrow B as it passes sequentially through the primary transfer positions of the image forming devices 2 (Y, M, C, and K).

[0063] Among them, the supporting roller 32a is configured as a driving roller that receives rotational power from a driving device not shown in the figure and is driven to rotate, the supporting roller 32b is configured as an exit roller that cooperates with the supporting roller 32a to maintain the belt position (surface) that is about to pass through or has just passed through the primary transfer position of the intermediate transfer belt 31, and the supporting roller 32c is configured as a tensioning roller.

[0064] Furthermore, the support roller 32d serves as an exit roller before secondary transfer of the intermediate transfer belt 31, the support roller 32e serves as a secondary transfer back roller, and the support roller 32f serves as an exit roller after the intermediate transfer belt 31 passes through the secondary transfer position. When the support roller 32e serves as a roller for supplying a voltage for secondary transfer, the voltage for secondary transfer is supplied from a power supply device (not shown).

[0065] Furthermore, the primary transfer device 25 of each image forming device 2 (Y, M, C, K) is arranged inside the intermediate transfer belt 31. The primary transfer device 25 also constitutes a part of the intermediate transfer device 3. The primary transfer device 25 is composed of a primary transfer roller, etc., and a primary transfer current is supplied to the primary transfer roller from a power supply device (not shown).

[0066] Furthermore, a secondary transfer device 35 is disposed on the outer peripheral surface of the portion of the intermediate transfer belt 31 supported by the support roller 32e. The secondary transfer device 35 allows the paper 9 to pass through and secondarily transfers the toner image on the intermediate transfer belt 31 to the paper 9. The secondary transfer device 35 is composed of a secondary transfer roller and the like.

[0067] In addition, a belt cleaning device 36 is arranged on the outer peripheral surface of the portion of the intermediate transfer belt 31 supported by the supporting roller 32a. The belt cleaning device 36 removes unnecessary colorants and other unnecessary substances remaining on the outer peripheral surface of the intermediate transfer belt 31 after the secondary transfer and cleans the outer peripheral surface of the intermediate transfer belt 31.

[0068] In the intermediate transfer device 3 , a portion of the outer peripheral surface of the intermediate transfer belt 31 that contacts the secondary transfer device 35 serves as a secondary transfer position TP2 where the toner image is secondary transferred.

[0069] The paper feeder 4 accommodates and feeds paper 9 to be fed to the secondary transfer position TP2 of the intermediate transfer device 3. The paper feeder 4 is arranged inside the housing 10 below the image forming devices 2 (Y, M, C, K).

[0070] The paper feeding device 4 is configured by arranging a container 41 for accommodating paper sheets, a feeding device 43 , and other devices.

[0071] The container 41 is a storage member having a loading plate 42 for loading and storing multiple sheets of paper 9 in a desired orientation. The container 41 is mounted so that it can be drawn out of the housing 10 for operations such as replenishing the paper 9. The feeder 43 is a device that repeatedly feeds out the paper 9 loaded on the loading plate 42 of the container 41 one by one using a feeder device such as multiple rollers.

[0072] The paper 9 may be any recording medium such as plain paper, coated paper, or thick paper that can be conveyed within the housing 10 and to which a toner image can be transferred and fixed, and its material and form are not particularly limited.

[0073] A paper feed transport path Rt1 is provided between the paper feed device 4 and the secondary transfer position TP2 of the intermediate transfer device 3. This paper feed transport path Rt1 transports the paper 9 located in the paper feed device 4 to the secondary transfer position TP2. This paper feed transport path Rt1 is composed of a plurality of transport rollers 44a to 44c that sandwich and transport the paper 9, and a plurality of guide members (not shown) that guide the transport of the paper 9 while ensuring a sufficient space for transporting the paper 9.

[0074] In the intermediate transfer device 3, the four-color toner images formed on the photosensitive drums 21 of the image forming device 2 (Y, M, C, and K) are subjected to primary transfer by the primary transfer device 25. These images are sequentially superimposed on the outer circumference of the intermediate transfer belt 31, which rotates in the direction indicated by arrow B. Afterwards, they are transported to the secondary transfer position TP2. Meanwhile, after the required paper 9 is delivered from the paper feed device 4, it is transported to the secondary transfer position TP2 via the paper feed and transport path Rt1 in coordination with the formation and transport of the toner images.

[0075] Thus, the toner image transported after primary transfer by the intermediate transfer belt 31 is transferred by the secondary transfer device 35 at the secondary transfer position TP2 in the intermediate transfer device 3 and is collectively secondary transferred onto one side of the paper 9 .

[0076] The fixing device 5 is configured to fix the toner image secondarily transferred by the intermediate transfer device 3 to the paper 9. The fixing device 5 is arranged inside the housing 10 below the secondary transfer position TP2 of the intermediate transfer device 3 and downstream in the conveyance direction of the paper 9.

[0077] The fixing device 5 is configured by arranging components such as a heating rotating body 51 and a pressing rotating body 52 in an internal space of a housing 50 provided with an introduction port and an outlet for the paper 9 .

[0078] The heating rotor 51 is a rotating body constructed of a roller, belt, or pusher type, rotating in the direction indicated by the arrow. It is heated by a heating unit (not shown) to maintain its outer surface at a desired temperature. The pressurizing rotor 52 is a rotating body constructed of a roller, belt, or pusher type, rotating in contact with the heating rotor 51 under the desired pressure. The pressurizing rotor 52 can also be heated by the heating unit.

[0079] In the fixing device 5 , the contact area between the heating rotator 51 and the pressing rotator 52 constitutes a nip portion (fixing processing portion) FN that performs heating, pressing, and other processes for fixing the unfixed toner image to the paper 9 .

[0080] A relay transport path Rt2 is provided between the secondary transfer position TP2 of the intermediate transfer device 3 and the fixing device 5. The relay transport path Rt2 is used to relay the secondary transferred paper 9 to the fixing device 5. The relay transport path Rt2 is formed by, for example, disposing a suction belt transport device 46 or the like.

[0081] Furthermore, an ejection transport path Rt3 is provided between the fixing device 5 and the discharge port 13. This ejection transport path Rt3 transports the paper 9 after fixing to the paper discharge port 13 in the housing 10 and discharges the paper into a paper discharge accommodating portion (not shown). This ejection transport path Rt3 is configured by arranging a pair of transport rollers (not shown), discharge rollers, and a plurality of guide members (not shown) for guiding the transport of the paper 9.

[0082] In the fixing device 5 , the paper 9 , after the secondary transfer has been completed in the secondary transfer device 35 , is introduced into the fixing processing section of the fixing device 5 via the relay transport path Rt2 .

[0083] As a result, the paper 9 is subjected to a fixing process by the fixing device 5 , and the toner image is fixed thereon, thereby forming a full-color image on one side of the paper.

[0084] Finally, the paper 9 after fixing is discharged to a paper discharge accommodating portion (not shown) via a discharge transport path Rt3 .

[0085] The image forming apparatus 1 outputs a single sheet of paper 9 with a full-color image formed thereon through the above-described operation. The image forming apparatus 1 can also form other types of images, including monochrome images such as black images.

[0086] <Structure of the developer supply device, etc.>

[0087] Furthermore, in the image forming apparatus 1, as shown in FIG. Figure 1 、 Figure 2 As shown, for each developing device 24 (Y, M, C, K) in the image forming device 2 (Y, M, C, K), the required amount of developer of the corresponding color is respectively supplied from the developer container 18Y, 18M, 18C, 18K which contains developer of different colors through the developer supply device 7.

[0088] The developer container 18 (Y, M, C, K) is a replaceable cartridge-type storage container and is used by being detachably mounted on the mounting device 17. When the developing device 24 uses a two-component developer, the developer container 18 (Y, M, C, K) stores toner of any one of the four colors (Y, M, C, K) or toner containing a small amount of carrier as developer, separated by color.

[0089] The developers stored in the developer containers 18 (Y, M, C, K) are respectively supplied to the developing devices 24 (Y, M, C, K) from the supply device 7 separately disposed below the mounting device 17 . Figure 1 、 Figure 2 Reference numeral 78 denotes a conveying pipe provided so as to convey the developer supplied from each supply device 7 to each developing device 24 (Y, M, C, K).

[0090] like Figure 2 As shown by the double-dashed line, a driving device 192 for driving a unit for discharging the developer in the developer container 18 is provided in the assembly device 17. Figure 2 As shown by the dotted line, the mounting device 17 is provided with a discharge port 17 a for discharging the developer supplied from the developer container 18 and conveying the developer to the supply device 7 (a receiving port 71 to be described later).

[0091] like Figures 2 to 4 As shown in the figures, the replenishing device 7 includes: a main body 70, which has a receiving port 71 for receiving the developer supplied from the developer container 18 (Y, M, C, K), a conveying path 72A, 72B for conveying the developer, and a delivery port 73 for delivering the developer in the conveying path 72A, 72B to a replenishing destination such as the developing device 24; developer conveying units 74, 75, which are separately arranged in a manner of rotating in the conveying path 72A, 72B; a delivery unit 76, which delivers the developer in the conveying path 72A, 72B to the delivery port 73; and a developer storage height detection device 6, which detects the storage height of the developer surface conveyed in the conveying path 72A.

[0092] The main body 70 is a container-shaped structure that is long in one direction (for example, the depth direction or the longitudinal direction indicated by the arrow Z). Two rows of conveying paths 72A and 72B extending parallel to the longitudinal direction are provided at its lower portion. Figure 3 、 Figure 4 In the figures, etc., the replenishing device 7 is shown in a state where an upper panel (cover) (not shown) of the main body 70 is removed.

[0093] The conveyance path 72A is a first conveyance path 72A, and the conveyance path 72B is a second conveyance path 72B.

[0094] like Figure 4 、, Figure 5 As shown in FIG. 1 and FIG. 2 , each of the first transport path 72A and the second transport path 72B is formed as a groove having a U-shaped cross-sectional shape and extending linearly.

[0095] In addition, the first conveying path 72A and the second conveying path 72B are separated by a plate-shaped partition wall 70b along the long side direction. On the other hand, at their two ends in the long side direction, they are connected to each other via the first connecting path 72C and the second connecting path 72D where the partition wall 70b does not exist, thereby forming a continuous conveying path.

[0096] like Figure 2 、 Figure 4 As shown, the receiving port 71 is provided at a position above and immediately before the upstream end portion of the first conveying path 72A in the developer conveying direction (D1) of the main body 70. The receiving port 71 is formed on an upper panel (not shown) of the main body 70. The receiving port 71 is connected to the developer discharge port 17a of the mounting device 17 of the developer container 18 in a manner opposite to the developer discharge port 17a. Figure 2 ).

[0097] like Figure 2 、 Figure 4 As shown, the delivery port 73 is provided at a portion offset outward from the second communication passage 72D (one end portion in the longitudinal direction of the main body 70 ).

[0098] The developer conveying unit 74 is a first conveying unit disposed in the first conveying path 72A, and the developer conveying unit 75 is a second conveying unit disposed in the second conveying path 72B.

[0099] like Figures 3 to 5As shown in FIG. 1 and FIG. 2 , the first conveying unit 74 is rotatably arranged in the first conveying path 72A, and includes a conveying member having a conveying portion 742. The conveying portion 742 is spirally arranged around a rotating shaft 741 at predetermined intervals with gaps therebetween. The second conveying unit 75 is rotatably arranged in the second conveying path 72B, and includes a conveying member having a conveying portion 752. The conveying portion 752 is spirally extended from a rotating shaft portion 751 at one end toward the other end with predetermined gaps therebetween.

[0100] Furthermore, the first developer conveying unit 74 and the second developer conveying unit 75 are rotated in a predetermined direction by the rotational power transmitted from the drive input shaft 77 a through the gear train mechanism 77 b .

[0101] Thus, in the first conveying path 72A, the developer is conveyed in the direction indicated by the arrow D1 by the rotation of the first conveying unit 74. In the second conveying path 72B, the developer is conveyed in the direction indicated by the arrow D2 by the rotation of the second conveying unit 75. The driving input shaft 77a is transmitted from the driving device 712 ( Figure 2 ) output rotational power.

[0102] The delivery unit 76 is configured to be located within the second communication passage 72D. The delivery unit 76 is composed of a rotating shaft 761, a spiral conveying portion 762, and a plate-shaped feed blade portion 763. The rotating shaft 761 is rotatably arranged on the main body 70 so as to pass through the first communication passage 72C and the second communication passage 72D between the partition wall 70b. The spiral conveying portion 762 is spirally and continuously projecting from the portion of the rotating shaft 761 extending from the second communication passage 72D to the delivery port 73. The plate-shaped feed blade portion 763 is axially arranged in the portion of the rotating shaft 761 located within the first communication passage 72C.

[0103] The delivery unit 76 is rotated in a predetermined direction by the rotational power transmitted from the drive input shaft 77 a to the rotation shaft 761 via the gear train mechanism 77 b , similarly to the first and second developer conveying units 74 and 75 .

[0104] Thus, in the delivery unit 76 , the developer in the second communication path 72D is delivered toward the delivery port 73 by the conveying screw 762 , and the developer in the first communication path 72C is conveyed toward the second conveying path 72B by the feeding blade 763 .

[0105] Furthermore, the delivery unit 76 is rotationally driven simultaneously with the rotational drive of the first developer conveying unit 74 and the second developer conveying unit 75 .

[0106] <Structure of the Developer Storage Level Detection Device>

[0107] Next, the developer storage level detection device 6 will be described.

[0108] First, regarding the storage height detection device 6, as shown in FIG. Figure 3 、 Figure 4 As shown in the figures, the replenishing device 7 is an example of an application object of the storage height detection device 6, and a part of the main body 70 of the replenishing device 7 provided with the first conveying path 72A is constituted as a main body 61, which includes: a first conveying unit 74 of the developer, which is arranged in the first conveying path 72A and is arranged to rotate in the first conveying path 72A; a swinging unit 64, which contacts the agent surface of the developer conveyed in the first conveying path 72A and swings at least following the storage height of the agent surface; and a detection unit 65, which detects the swinging state of the swinging unit 64.

[0109] The main body 61 is a portion of the main body 70 of the supply device 7 where at least the first conveying path 72A is provided. Figures 3 to 6 As shown, the main body 61 in the first embodiment has a structure in which a protrusion is provided. This protrusion protrudes outward in a direction substantially perpendicular to the developer conveying direction D1 from a portion of the first conveying path 72A in the main body 70, thereby forming a recessed space. The recessed space in the protrusion is used as a space for arranging a portion of the swing unit 64.

[0110] As described above, the first conveying unit 74 is arranged to rotate within the first conveying path 72A, and is composed of a conveying member having a structure including conveying portions 742 spirally provided at intervals around a rotating shaft 741 .

[0111] The swing unit 64 is composed of a plate-like member that is long in one direction. Figures 3 to 5 As shown in FIG. 1 , one end portion of the swing unit 64 in the longitudinal direction is fixedly attached to a swing support shaft 66. This swing support shaft 66 is swingably disposed within the recessed space of the protruding portion of the main body 61. The other end portion of the swing unit 64 in the longitudinal direction is disposed so as to pass over the first conveying unit 74 and contact the developer surface (S) that is the surface of the developer stored in the first conveying path 72A. Furthermore, the swing unit 64 is disposed so that its longitudinal direction is substantially perpendicular to the rotation axis 741 of the first conveying unit 74.

[0112] The swing support shaft 66 supporting the swing unit 64 is provided so as to be rotatable in a direction substantially perpendicular to the rotation axis 741 of the first conveying unit 74 and transverse to the recessed space of the protruding portion of the main body 61. Furthermore, one end of the swing support shaft 66 is provided so as to protrude outward from a side surface of the protruding portion of the main body 61.

[0113] like Figures 3 to 5 As shown in FIG. 6 , a detected plate 67, an example of a detected unit actually detected by the detection unit 65, is fixedly mounted on the end of the protruding portion of the swing support shaft 66. The detected plate 67 is formed, for example, of a fan-shaped member. Furthermore, the detected plate 67 swings in conjunction with the swing unit 64 by transmitting the swing of the swing unit 64 via the swing support shaft 66.

[0114] like Figure 5 As shown in (A), the swing unit 64 is fixedly mounted on the swing support shaft 66, so that the swing unit 64 swings in the direction indicated by the double arrow with the swing support shaft 66 as a fulcrum. Figure 5 (B) Figure 7 As shown, the swinging front end portion of the swinging unit 64 as the other end portion can contact the developer surface (S) present in the first conveying path 72A, and the swinging unit 64 swings at least following the storage height of the developer surface (S).

[0115] Here, the storage height is the dimension from the agent surface (S) of the developer existing in the first conveying path 72A to the bottom surface of the first conveying path 72A, and is a dimension roughly determined by the amount (volume) stored and accumulated in the first conveying path 72A.

[0116] The detection unit 65 is for detecting the swing state of the swing unit 64 . In the first embodiment, the detection unit 65 is for detecting the state of the detection target plate 67 that swings in conjunction with the swing unit 64 .

[0117] The detection unit 65 is constructed using, for example, a transmissive photosensor, which is an example of a unit that detects the plate to be detected 67 by transmitting or blocking light. The detection unit 65, which is constructed using a transmissive photosensor, includes a detection section 65a for detecting whether the light receiving section 652 receives the detection light emitted by the light emitting section 651. The detection unit 65, which is constructed using a transmissive photosensor in Embodiment 1, employs a type of detection unit including a single detection section 65a.

[0118] On the other hand, the plate to be detected 67 is formed as a member having light shielding properties when the detection unit 65 is a transmissive optical sensor. Figure 5As shown in (B), the detection plate 67 is configured so that the detection unit 65 detects the state of the swing unit 64 when it at least follows and swings when the storage height of the developer surface (S) present in the first conveying path 72A becomes lower (close to the minimum detection height Mlow).

[0119] In addition, if Figure 3 As shown in FIG. 1 and FIG. 2 , the detection unit 65 is provided in a portion 61 d of the main body 61 (the main body 70 of the replenishing device 7 ) that is outside the first transport path 72A.

[0120] The portion where the detection unit 65 is provided in the first embodiment, namely the outer portion 61d, is configured to be adjacent to one side of the protruding portion of the main body 61 having the recessed space where the base end of the swing unit 64 is located. Thus, the portion where the detection unit 65 is provided is isolated from the first transport path 72A.

[0121] In addition, in the storage height detection device 6, as shown in FIG. Figures 3 to 6 As shown in the figures, a first conveying unit 74 (A) having a conveying portion 68 without a conveying part 742 is applied as the above-mentioned first conveying unit 74, and the swing unit 64 is configured to swing in a state where the conveying portion 68 is not present in the first conveying unit 74 (A).

[0122] And, as Figure 2 、 Figure 4 As shown, the storage height detection device 6 includes a determination unit 69 for determining whether there is developer in the first conveying path 72A based on a detection signal output from the detection unit 65. The determination unit 69 is configured to determine that there is no developer through information processing described later.

[0123] like Figure 4 、 Figure 6 As shown, the first conveying unit 74 (A) is interrupted at a portion corresponding to the area where the swing unit 64 for accommodating the height detection device 6 is present, and the spiral conveying portion 742 is not provided. The portion where the conveying portion 742 is interrupted and made non-existent (the portion where only the rotating shaft 741 exists, in this case the portion where the eccentric shaft 743 described later exists) is constituted as a non-conveying portion 68.

[0124] In this case, if Figure 4 、 Figure 5 As shown in (A) and the like, the swing unit 64 is in a state where it exists at least on the upper side of the non-transmission portion 68 (the rotating shaft 741 in the non-transmission portion. In fact, it is the eccentric shaft 743 described later). In addition, it is configured so that the free end on the side opposite to the base end supported by the swing support shaft 66, that is, the swing front end portion 64a, passes over the eccentric shaft 743 described later of the non-transmission portion 68 and exists in the first transmission path 72A.

[0125] In addition, if Figure 6 As shown in FIG. 1 , the non-transportation portion 68 in the first transport unit 74 (A) uses an eccentric shaft 743 offset from the axis of the rotation shaft 741 at a portion other than the non-transportation portion 68 as a rotation shaft.

[0126] like Figure 5 As shown in (B), the eccentric shaft 743 is constructed to be eccentric with a specified eccentricity α, so that when the swing unit 64 is in contact with the eccentric shaft 743, the swing front end 74a can reach the minimum detection height (MLow) of the developer surface (S).

[0127] like Figure 6 As shown in the figures, the eccentric shaft 743 in embodiment 1 has the following shape (crank shape): after rising from the rotating shaft 741 on both sides of the non-transmission portion 68 by a height of eccentricity α in the vertical direction, it has a straight shaft portion parallel to the axial direction of the rotating shaft 741 within the range of the non-transmission portion 68.

[0128] In the storage height detection device 6, the eccentric shaft 743 is used as the rotation axis in the non-transporting portion 68. Therefore, the swing unit 64 can rotate in the first transport path 72A, for example, when there is no developer or the developer is insufficient. Figure 5 As shown, the lower surface thereof may periodically contact the outermost circumference 743a or the innermost circumference 743b of the eccentric shaft 743 described later without the conveying portion 68 in the rotating first conveying unit 74 (A) and thereby oscillate.

[0129] Therefore, as described above, the swing unit 64 in the storage height detection device 6 not only swings in accordance with the storage height of the developer surface (S), but also periodically swings up and down due to contact with the rotating eccentric shaft 743 .

[0130] The outermost circumference 743 a is the portion located outermost relative to the axis of the rotating shaft 741 of the eccentric shaft 743 , and the innermost circumference 743 b is the portion located innermost relative to the axis of the rotating shaft 741 of the eccentric shaft 743 .

[0131] like Figure 2 As shown, the determination unit 69 is configured as a part (functional portion or circuit portion) of the control unit 15 configured by a microcomputer or the like for controlling the operation of the image forming apparatus 1 .

[0132] The determination unit 69 is a unit that can determine whether or not there is developer in the first conveying path 72A based on the detection signal output from the detection unit 65 , and determines that there is no developer through the next information processing and outputs the signal indicating the determination.

[0133] That is, in the discrimination unit 69, if Figure 8 As shown, the detection signal obtained from the detection unit 65 is sampled at an interval (Tc / N) obtained by dividing the time Tc required for the first conveying unit 74 (A) to rotate one circle by a predetermined number N (for example, 30).

[0134] Next, the discrimination unit 69 is configured to discriminate as "no developer" based on the information of the number N of detection signals sampled within the required time Tc, when the ratio [(Lm / N)·100] occupied by the detection signal Lm is greater than the threshold value Dx for judging the absence of developer, and output the discriminated signal to the control unit 15, etc., wherein the detection signal Lm is below the output level determined as the storage height of the developer surface (S) is relatively low (minimum detection height: MLow).

[0135] In embodiment 1, as Figure 8 As shown in FIG. 1 , the output level of the detection signal Lm when the storage height is relatively low is set to, for example, a second output value V2. Furthermore, the output level of the detection signal Hm when the storage height of the developer surface (S) is relatively high is set to, for example, a first output value V1 (>V2) that is higher than the second output value V2. Furthermore, the threshold value Dx for determining that the developer is out of developer is set to, for example, 10%.

[0136] In addition, in the storage height detection device 6, as shown in FIG. Figure 5 As shown in (B), the swing support shaft 66 serving as a fulcrum during swinging is arranged above the uppermost portion 742t of the conveying portion 742 serving as the uppermost portion of the first conveying unit 74 (A).

[0137] Furthermore, in the receiving height detection device 6, as shown in FIG. Figure 4 As shown in FIG. 1 and FIG. 2 , the storage height detection device 6 is arranged at a position downstream of the receiving port 71 in the developer conveying direction D1 in the first conveying path 72A and close to the receiving port 71. More specifically, the storage height detection device 6 is arranged so that its swing unit 64 is located at a position deviated from a position directly below the receiving port 71 in the first conveying path 72A (at a position downstream of the receiving port 71 in the developer conveying direction D1).

[0138] <Operation of the Developer Supply Device>

[0139] Next, the operation of the developer supply device 7 having the above-mentioned structure will be described. Figure 2 As shown, the charging device 7 is controlled by the control unit 15 to operate.

[0140] That is, in the image forming apparatus 1, as Figure 2 As shown, the amount of developer (for example, the amount of toner in the case of two-component developer: concentration) stored in each of the developing devices 24 (Y, M, C, K) is detected by the detection unit 28. This detection information is sent to the control unit 15 for management. If the control unit 15 determines that the toner in any of the developing devices 24 (Y, M, C, K) is insufficient, the replenishment drive device 712 is controlled to operate at the required timing. The replenishment drive device 712 rotates the delivery unit 76 of the replenishment device 7 connected to the developing device 24 of the color determined to be insufficient in toner. This activates the replenishment device 7.

[0141] At this time, in the replenishing device 7, the rotational power of the driving device 712 for replenishment is also transmitted to the first conveying unit 74 (A) and the second conveying unit 75, and they are rotationally driven in predetermined directions.

[0142] Thus, the developer stored in the first conveying path 72A and the second conveying path 72B is conveyed along the predetermined conveying directions D1 and D2 ( Figure 4 )Transmit.

[0143] That is, the developer in the supply device 7 is transported back and forth between the first transport path 72A and the second transport path 72B while passing through the first connecting path 72C and the second connecting path 72D, and is transported in a circular manner as a whole. In addition, when a portion of the developer is transported and moved in the second connecting path 72D, it is transported toward the delivery port 73 by the transport force of the spiral transport portion 762 of the delivery unit 76.

[0144] In this way, in the supply device 7, the developer contained in the first conveying path 72A and the second conveying path 72B of the main body 70 is delivered from the delivery port 73 via the second connecting path 72D, and the delivered developer is then delivered to the developing device 24 of the color judged to be insufficient in the conveying pipe 78, resulting in the supply of the developer.

[0145] In addition, if Figure 2 As shown, the supply device 7 detects the storage height of the developer surface (S) in the first conveying path 72A in the main body 70 through the developer storage height detection device 6. In addition, the detection result of the detection unit 65 is sent to the control unit 15 (the judgment unit 69 therein) for management.

[0146] Then, when the discrimination unit 69 in the control unit 15 determines that the storage height of the developer in the first conveying path 72A becomes low and is in a state of insufficient developer stored in the main body 70 (a state of no developer), control is performed so that the driving device 192 of the assembly device 17 is driven for the required time, wherein the assembly device 17 is connected to the supply device 7 that is judged to be in the state of insufficient developer.

[0147] As a result, the unit for discharging the developer in the developer container 18 in the assembly device 17 is activated, and the developer in the developer container 18 is supplied to the replenishing device 7 via the assembly device 17 for replenishment. At this time, the developer in the developer container 18 is discharged from the discharge port 17a in the assembly device 17, and then falls to the first conveying path 72A through the receiving port 71 of the replenishing device 7 to be supplied.

[0148] <Operation of the Developer Storage Level Detection Device>

[0149] Next, the operation of the developer storage level detection device 6 will be described. Here, the storage level detection device 6 detects the storage level of the developer present in the first transport path 72A in the main body 70 when the replenishing device 7 is operating.

[0150] In the storage height detection device 6, the swinging unit 64 swings at least to follow the storage height of the agent surface (S) of the developer stored in the part where the no transport portion 68 exists in the first transport unit 74 (A) in the first transport path 72A (hereinafter referred to as the "detection area"), and the detection unit 65 detects the swinging state of the swinging unit 64.

[0151] In this case, in the portion of the first conveying path 72A where the conveying portion 68 is absent, the developer cannot directly receive the conveying force of the conveying portion 742 of the first conveying unit 74(A), and thus temporarily stagnates. However, this stagnant developer is squeezed by the developer conveyed from the upstream side in the developer conveying direction D1, and is thus sequentially conveyed through the portion where the conveying portion 68 is absent.

[0152] In addition, in the storage height detection device 6, in the above-mentioned detection area, the eccentric shaft 743 without the transmission part 68 in the first transmission unit 74 (A) rotates around the rotation axis 741, so that the eccentric shaft 743 moves in a manner passing under the swing unit 64.

[0153] Here, assuming that a sufficient amount of developer is stored in the detection area of the first transport path 72A, the swing unit 64 operates as follows to detect the storage height of the developer at this stage.

[0154] That is, when there is a sufficient amount of developer, the swing unit 64 may be in the following state: Figure 5 (A), in a state where the eccentric shaft 743 without the transmission portion 68 in the first transmission unit 74 (A) rotating in the detection area is in contact with the outermost peripheral portion 743a and is swung in a direction to raise (lift) the oscillating tip portion 64a; and Figure 7 As shown, regardless of the position of the eccentric shaft 743 without the conveying portion 68 in the rotating first conveying unit 74 (A), the state is such that the front end portion 64a of the swing does not contact the eccentric shaft 743 and swings to a position where it contacts the agent surface (S) of the developer.

[0155] At this time, no matter which swing state the detection plate 67 that swings in conjunction with the swing unit 64 becomes, Figure 5 (A) and Figure 7 As shown in FIG, the state is swung to a position where the detection light of the detection portion 65a in the detection unit 65 is blocked. Figure 9 As illustrated, the detection output of the detection unit 65 at this time is obtained as a detection signal Hm composed of a predetermined first output value ( V1 ).

[0156] Then, in the storage height detection device 6 at this time, the output signal output from the detection unit 65 is sampled in the determination unit 69 as described above, and based on the information of the sampled number of detection signals, it is determined whether the ratio of the detection signal Lm that is less than the second output value V2 within the required time T is greater than the threshold value Dx (for example, 10%). This stage is as follows Figure 9 As shown, during the period in which the detection signal Hm of a relatively high output level (first output value: V1) is continuously obtained from the detection unit 65, the ratio occupied by the detection signal Lm is smaller than the threshold value Dx.

[0157] Therefore, at this time, the determination unit 69 of the storage height detection device 6 determines that “developer is present” with respect to the detection output obtained from the detection unit 65 .

[0158] On the other hand, assuming that the developer stored in the detection area of the first conveying path 72A is gradually decreasing due to the replenishment operation, the swing unit 64 is in the following state at this stage to detect the developer storage height.

[0159] That is, in the stage of reducing the developer, the storage height of the developer surface (S) begins to become relatively low, so the swing unit 64 that makes the swing front end 64a contact the developer surface (S) becomes a state of swinging in the direction of gradually lowering the swing front end 64a.

[0160] At this time, when the developer is reduced to a height where the developer storage height is close to the minimum detection height MLow, as shown in FIG. Figure 5 As shown in (B), the detection plate 67 that swings in conjunction with the swing unit 64 may sometimes swing to a position where it does not block the detection light of the detection portion 65a in the detection unit 65. Figure 9 As illustrated, the detection output of the detection unit 65 at this time is obtained as a second output value (V2) of a predetermined relatively high output level.

[0161] The length of time during which the second output value ( V2 ) is output at this time gradually changes as described below.

[0162] First, in the stage just before the swing unit 64 comes into contact with the innermost circumference 743b of the eccentric shaft 743 without the transmission portion 68 and swings, the swing unit 64, which has been swinging so that the swing front end portion 64a moves downward, comes into a state of swinging so that it comes into contact with the innermost circumference 743b and the outermost circumference 743a of the rotating eccentric shaft 743 and is lifted upward ( Figure 5 (A)), therefore, the second output value (V2) is obtained as the output value of the relatively short time t1, t2, t3.

[0163] Then, when Figure 5 As shown in (B), when the swing unit 64 comes into contact with the innermost circumference 743b of the eccentric shaft 743 without the transmission portion 68 and swings, the swing unit 64 swings in a manner following the movement of the innermost circumference 743b of the rotating eccentric shaft 743, and the time for which the swing front end 64a contacts the lowest detection height MLow becomes the longest, and the detected plate 67 is also kept in the state of being swung to the position where it does not block the detection light for the longest time ( Figure 5 (B)), therefore, the second output value (V2) is obtained as an output value of a relatively long time t4 (> t3> t2> t1) which is substantially constant ( Figure 9 ).

[0164] Furthermore, at this time, the swing unit 64 contacts the outermost circumference 743a of the eccentric shaft 743 of the rotating first conveyor unit 74(A) without the conveying portion 68 in the detection area, and also swings in a direction in which the swing tip 64a rises. This swinging state continues while the first conveyor unit 74(A) rotates.

[0165] like Figure 5 As shown in (A), the plate to be detected 67 at this time is swung to a position where it blocks the detection light of the detection portion 65a in the detection unit 65. Figure 9 As illustrated, the detection output of the detection unit 65 at this time is obtained as the first output value ( V1 ) again.

[0166] Then, in the storage height detection device 6 at this time, the output signal output from the detection unit 65 is sampled in the determination unit 69 as described above, and based on the information of the sampled number of detection signals, it is determined whether the ratio of the detection signal Lm that is less than the second output value V2 within the required time T is greater than the threshold value Dx. Figure 9 As shown, this stage is a period in which the detection signal Lm of a relatively low output level (second output value: V2) is intermittently obtained from the detection unit 65. Therefore, the time when the ratio occupied by the detection signal Lm becomes greater than the threshold value Dx comes.

[0167] Therefore, the determination unit 69 of the storage height detection device 6 determines that “developer is present” at the time point (ta) when the ratio of the detection signal Lm becomes equal to or greater than the threshold value Dx with respect to the detection output obtained from the detection unit 65 .

[0168] Therefore, the storage height detection device 6 can reliably detect the storage height of the developer in the first conveying path 72A of the main body 70 of the developer supply device 7. In particular, the storage height of the developer can be reliably detected compared to a case where the following configuration is not adopted: the first conveying unit 74 (A) disposed in the first conveying path 72A has a non-conveying portion 68; the swing unit 64 is configured to swing while being located in the non-conveying portion 68; and the determination unit 69 samples the detection signal at intervals obtained by dividing the time T required for the first conveying unit 74 (A) to rotate once by a predetermined number of times. When the ratio of the detection signal below the output level (first output value: V1) indicating a relatively low storage height within the required time T becomes greater than or equal to the threshold value E1, the determination unit 69 determines that there is no developer.

[0169] In addition, according to the storage height detection device 6, for example, there is no need to set up a space for storing and detecting a developer different from the first conveying path 72A, and there is no need to expand the first conveying path 72A to set up the swing unit 64, and the storage height of the developer in the first conveying path 72A can be detected.

[0170] Furthermore, according to the storage height detection device 6, the eccentric shaft 743 is applied to the non-transport portion 68 of the first transport unit 74 (A). Therefore, the width (amplitude) of the swing unit 64 in the direction of swinging (particularly the downward direction) within the first transport path 72A can be easily increased compared to a case where the eccentric shaft 743 is not applied. Furthermore, by appropriately setting the eccentricity α of the eccentric shaft 743, it is also easy to reliably detect the storage height, especially when the developer is low (particularly when the developer is close to the minimum detection height Mlow).

[0171] Furthermore, in this storage height detection device 6, the swing support shaft 66, which serves as the fulcrum for the swinging of the swing unit 64, is positioned above the uppermost portion 742t of the first conveying unit 74(A). Therefore, compared to a case where the swinging tip 64a of the swing unit 64 is not positioned in such a position, it is easier for the swinging tip 64a of the swing unit 64 to detect the storage height at which the developer in the first conveying path 72A has become low. Furthermore, since the detection unit 65 is positioned in the portion 61d that becomes the outer side of the first conveying path 72A, the detection unit 65 is less likely to be contaminated by the developer than when it is not positioned in such an outer portion 61d, thereby enabling stable detection.

[0172] Furthermore, in the storage height detection device 6, the swing unit 64 is particularly arranged at a position (i.e., downstream of the receiving port 71 in the developer conveying direction D1) in the first conveying path 72A of the supply device 7. Figure 4 ), therefore, compared with a case where it is not arranged at such a position (for example, a position at the end portion on the downstream side of the developer conveying direction D1 in the first conveying path 72A, a position at a certain point in the second conveying path 72B, etc.), since it is close to the receiving port 71 that reflects the state of the amount of developer supplied from the developer container 18, the storage height at which the developer becomes less can be detected efficiently and quickly.

[0173] Moreover, since the swing unit 64 is configured to be located at a position deviated from the position directly below the receiving port 71, it is possible to avoid the developer received from the receiving port 71 in the supply device 7 from easily accumulating above the swing unit 64, thereby preventing the swinging of the swing unit 64 from becoming unstable, and also to avoid a decrease in detection accuracy.

[0174] <Additional Structure Related to the Storage Height Detection Device of Embodiment 1>

[0175] In addition, in the storage height detection device 6 , the output level determined to be a relatively low storage height is set, for example, as follows.

[0176] like Figure 10 As shown, the output level determined here for a relatively low storage height is the minimum detection height MLow in the detection area of the first conveying path 72A (the distance J between the agent surface (S) of the developer and the lowest bottom surface portion of the first conveying path 72A when the minimum detection height is set).

[0177] First, regarding the output level determined to be relatively low at the storage height, that is, the minimum detection height MLow(J), as shown in FIG. Figure 11As shown, the level is set so that the developer supply amount delivered from the delivery port 73 by the delivery unit 76 does not fall below a predetermined minimum amount Km. When the output level is set to a level below the minimum amount Km, the developer supply amount stored in the first conveying path 72A and the second conveying path 72B may become too small. As a result, the developer supply amount from the supply device 7 to the developing device 24 may be insufficient, resulting in a decrease in the developer density (and thus, the image density).

[0178] In addition, regarding the output level determined to be relatively low at the storage height, that is, the minimum detection height MLow(J), as shown in FIG. Figure 11 As shown, the level is set so that the remaining amount of developer stored in the developer container 18 does not exceed the predetermined target remaining amount Pm. If the output level is set to a level exceeding the target remaining amount Pm, the developer supply device 7 detects that there is no developer when the remaining amount of developer in the developer container 18 is relatively large, and it is determined that there is no developer in the developer container 18. As a result, a large amount of developer may remain in the developer container 18 and cannot be used, resulting in waste.

[0179] Regarding output levels, such as Figure 11 As shown in FIG. 1 , it is preferable to set the output level within the first setting range that satisfies a level not lower than the minimum level Km and a level exceeding the target remaining level Pm. Furthermore, the target remaining level Pm may also vary depending on humidity, developer particle size, and the like. Therefore, for example, a configuration may be employed in which target remaining levels Pm corresponding to these differences are prepared in advance, and output levels corresponding to the differences in the target remaining levels Pm are set.

[0180] In addition, when the minimum detection height MLow (J) is selected, the shape of the detected plate 67, the configuration position of the detection unit 65, etc. can be adjusted in the following manner: the detected plate 67 in the swinging unit 64 that is in a state of swinging in contact with the minimum detection height MLow is detected by the detection part 65a of the detection unit 65 (in this example, moved to a position that does not block the detection light).

[0181] [Implementation Method 2]

[0182] Figure 12 This is a diagram showing a portion of a developer supply device 7 including a developer storage level detection device 6 according to a second embodiment of the present disclosure.

[0183] The developer storage height detection device 6 and the supply device 7 of embodiment 2 are composed of the same structure as the developer storage height detection device 6 and the supply device 7 of embodiment 1, except that part of the structure of the detection unit 65 and the swing unit 64 in the storage height detection device 6 is changed.

[0184] like Figure 12 As shown, the detection unit 65 in the storage height detection device 6 of the second embodiment is composed of a reflective-type optical sensor (e.g., a reflective type other than the type used for glossiness discrimination). This reflective-type optical sensor is an example of a unit that detects the presence or absence of light reflection on the detection plate 67 in the swing unit 64. This reflective-type optical sensor includes a light-emitting and light-receiving unit 655 that emits detection light and receives reflected light after the detection light is reflected. Furthermore, when using the detection unit 65 composed of this reflective-type optical sensor, the detection plate 67 in the swing unit 64 is composed of a member having light-reflecting properties that reflect light.

[0185] In this storage height detection device 6, the light emitting and receiving portion 655 of the detection unit 65, which is a reflective optical sensor, is arranged at a position where it can face the detection plate 67 of the swing unit 64. In this case, unlike a transmissive optical sensor, it is not necessary to arrange two components, namely the light emitting portion 651 and the light receiving portion 652; a single component is sufficient.

[0186] Therefore, according to the storage height detection device 6 , it is possible to detect the storage height of the developer surface (S) in the first conveying path 72A while achieving space saving of the device.

[0187] [Modification]

[0188] The present disclosure is not limited to the contents exemplified in the above-mentioned Embodiments 1 and 2, and includes, for example, the following modified examples.

[0189] In the storage height detection device 6, the detection unit 65 may also be formed of a reflective-type optical sensor for glossiness discrimination. This reflective-type optical sensor is an example of a unit that detects the detected plate 67 in the swing unit 64 based on differences in the amount of reflected light. In this case, the detected plate 67 in the swing unit 64 is formed of a member having light reflectivity that causes the amount of reflected light to vary depending on its swinging posture. This optical sensor also includes a single light-emitting and light-receiving unit 655, similar to the reflective-type optical sensor described above.

[0190] When a detection unit 65 composed of a reflective light sensor for glossiness discrimination is used, the amount of reflected light changes according to the swinging state of the detection plate 67, so that the difference in the storage height of the developer surface (S) located in the first conveying path 72A can be detected in detail.

[0191] In addition, in the storage height detection device 6 of the first embodiment, the detection unit 65 is composed of a transmissive optical sensor, such as Figure 13As shown, a detection unit 65 (B) including two or more detection portions 65 a for detecting transmission or blocking of light may be employed. Figure 13 The detection unit 65 (B) shown is a detection unit composed of a transmissive optical sensor having three detection parts 65a1, 65a2, and 65a3.

[0192] When the detection unit 65 (B) including two or more detection portions 52 a is used, the difference in the storage height of the developer surface (S) in the first conveying path 72A is detected at three or more different levels.

[0193] Furthermore, in the storage height detection device 6 ( Figure 12 ), the detection unit 65 composed of a reflective optical sensor may also be Figure 13 As in the illustrated modification, a detection unit 65 (B) is employed that includes two or more detection sections 65 a for detecting the presence or absence of light reflection.

[0194] When the detection unit 65 (B) including two or more detection portions 65 a is used, the difference in the storage height of the developer surface (S) in the first conveying path 72A is detected at three or more different levels.

[0195] In addition, in the storage height detection device 6 of the first and second embodiments and the above-mentioned modified examples, it is also possible to Figure 2 As shown by the two-dot chain line, the measuring unit 19 for measuring the humidity near the main body 61 is provided, and the determining unit 69 is configured to have a function of changing the threshold E1 according to the humidity measured by the measuring unit 19.

[0196] In this case, since the bulk density of the developer contained in the first conveying path 72A and the like tends to decrease and the height of the developer surface (S) tends to slightly increase under relatively low humidity conditions (e.g., when the humidity is 15% RH or less), the determination unit 69 changes the threshold value E1 to a value greater than the threshold value Ds used under normal temperature and humidity conditions (22°C, 55% RH). Conversely, since the bulk density of the developer contained in the first conveying path 72A and the like tends to increase and the height of the developer surface (S) tends to slightly decrease under relatively high humidity conditions (e.g., when the humidity is 85% RH or more), the determination unit 69 changes the threshold value E1 to a value smaller than the threshold value Ds used under normal temperature and humidity conditions.

[0197] According to the storage height detection device 6 configured in this manner, the storage height of the developer surface (S) located in the first conveying path 72A can be accurately detected without being affected by humidity.

[0198] In embodiments 1 and 2, a structural example is shown in which the developer storage height detection device 6 is used as a storage height detection device in the developer supply device 7 in the image forming device 1, but the disclosed storage height detection device 6 can also be applied to other device parts that transport and process the developer.

[0199] For example, in an image forming device that forms an image composed of a developer, the storage height detection device can be composed of the disclosed storage height detection device 6 when it has the following structural part, which includes: a main body, which has a conveying path for conveying the developer; a developer conveying unit, which is configured to rotate within the conveying path and has a conveying part spirally arranged around the rotating axis; and a storage height detection device, which detects the storage height of the agent surface of the developer conveyed in the conveying path.

[0200] In the first and second embodiments, the swing unit 64 is exemplified as being formed of a plate-like member. However, the present invention is not limited thereto, and the swing unit 64 may have a columnar outer shape (including a cylinder), for example.

[0201] Regarding the image forming apparatus 1 , image forming apparatuses of other forms and types may be employed.

Claims

1. A developer storage height detection device, wherein: The developer storage height detection device comprises: a main body provided with a conveying path for conveying the developer; a developer conveying unit configured to rotate within the conveying path and having a conveying portion spirally disposed around a rotation shaft and conveying the developer in an axial direction of the rotation shaft; a swing unit that contacts a surface of the developer conveyed in the conveying path and swings at least in accordance with a storage height of the developer surface; a detection unit configured to detect a swinging state of the swing unit; as well as a determination unit for determining the presence or absence of developer based on the detection signal output from the detection unit, The conveying unit has a non-conveying portion, which is a portion where the conveying part is interrupted and does not exist, and the rotating shaft is configured as an eccentric shaft with an offset axis in the non-conveying portion. The swing unit is configured to be present in the non-transmission portion and to swing up and down when in contact with the eccentric shaft, and the swing front end portion of the swing unit is configured to be able to swing to a position below the rotation axis. The discrimination unit samples the detection signal at an interval obtained by dividing the time required for the conveying unit to rotate one circle by a predetermined number, and outputs a signal discriminating that there is no developer when the ratio of the detection signal below the output level determined as the relatively low storage height within the required time is above a threshold.

2. The developer storage height detection device according to claim 1, wherein: The swing unit includes a detected portion that swings in conjunction with the swing unit. The detection unit is composed of a unit that detects the detection portion by transmitting or blocking light.

3. The developer storage height detection device according to claim 1, wherein: The swing unit is provided with a light-reflective detection unit that swings in conjunction with the swing unit. The detection unit is composed of a unit that detects the detected unit based on the presence or absence of light reflection.

4. The developer storage height detection device according to claim 1, wherein: The swing unit is provided with a light-reflective detection unit that swings in conjunction with the swing unit. The detecting unit is configured to detect the detected unit by a difference in the amount of reflected light.

5. The developer storage height detection device according to claim 2, wherein: The detection unit includes two or more detection sections for detecting transmission or blocking of the light.

6. The developer storage height detection device according to claim 3, wherein: The detection unit includes two or more detection sections for detecting the presence or absence of reflection of the light.

7. The developer storage level detection device according to any one of claims 1 to 6, wherein: The developer storage level detection device includes a measuring unit that measures the humidity near the main body. The determination unit has a function of changing the threshold value according to the difference in humidity measured by the measurement unit.

8. A developer supply device, wherein: The developer supply device comprises: a main body having a receiving port for receiving developer supplied from a developer container, a conveying path for conveying the developer, and a delivery port for delivering the developer in the delivery path to a supply destination; a developer conveying unit configured to rotate within the conveying path and having a conveying portion spirally provided around a rotation axis; a delivery unit that delivers the developer in the conveying path toward the delivery port; and a storage height detection device for detecting the storage height of the developer surface conveyed in the conveying path; The storage height detection device is constituted by the developer storage height detection device according to any one of claims 1 to 7.

9. The developer supply device according to claim 8, wherein: The level at which the storage height is determined to be low is a level at which the amount of the developer delivered to the delivery outlet by the delivery unit does not fall below a predetermined minimum amount.

10. The developer supply device according to claim 8 or 9, wherein: The developer container includes a feeding unit that is driven to feed the developer toward the receiving port when receiving a signal output from the discrimination unit indicating that the developer is absent. The level determined as the storage height being low is a level at which the remaining amount of the developer stored in the developer container does not exceed a predetermined target remaining amount.

11. An image forming apparatus, wherein: This image forming apparatus includes the developer storage level detection device according to any one of claims 1 to 7.

12. An image forming apparatus, wherein: This image forming apparatus includes the developer supply device according to any one of claims 8 to 10.

Images