Image reading apparatus

Abstract

To provide an image reader capable of grasping the height of an original platen without lowering the original platen to the lowest position, shortening moving time to the height of an intermediate position and grasping the lowering of the original platen due to overload.SOLUTION: An image reading device includes a loading table 1 for loading documents, a lifting means for lifting the loading table 1, a taking-in means for taking in the uppermost document loaded on the loading table 1, a side plate 50 arranged at a position facing a side surface of the loading table 1, a reflection part provided on one of the side surface of the loading table 1 and the side plate 50, a light reflection type sensor 60 provided on the other of the side surface of the loading table 1 and the side plate 50 where the reflection part is not provided, and a height calculation means for calculating the height of the loading table 1. The height calculating means calculates the height of the loading base 1 based on a light receiving output value by the light reflection type sensor 60.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an original feeding device capable of feeding an original and an image reading device. [Background technology]

[0002] A document feeder that sequentially separates and feeds documents from the top of a plurality of documents loaded on a document table that can be raised and lowered by driving a motor, and an image reading device that reads images of the documents being fed are known. In such devices, when a small number of documents are loaded relative to the maximum loadable amount on the document table, a method is known in which the document table is kept waiting at an intermediate position within its movable range to shorten the time it takes for the document table to rise.

[0003] In the device described above, a sensor is provided to detect when the document table is at its lowest home position, and the position of the document table is controlled by counting motor pulses associated with motor drive, with the sensor position as the origin. Therefore, in order to accurately position the document table, it is necessary to periodically lower the document table to its lowest home position to initialize the count value.

[0004] When performing such a position control operation of the document table while keeping the document table at a standby position in the middle of its movable range, the following problem occurs: If the document table is lowered to the home position and repositioned each time the feeding of a stack of documents loaded on the document table is completed, the document table will first be lowered to the lowest position and then raised to the middle position again, which takes time to raise and lower the document table and increases the user's waiting time.

[0005] In Patent Document 1, an identification portion that can be identified by an imaging means is provided on the side of the document table, and the imaging means is used to detect the intermediate height of the document table.

[0006] In Patent Document 2, a platen origin position detection sensor and a movement amount detection encoder are used to detect the intermediate height of the platen from the amount of movement from the origin position. Overload on the platen caused by user error or the like is addressed by providing a torque limiter in the transmission path of the driving force from the motor to the platen. Therefore, a separately provided sensor detects an overload on the torque limiter, and when the sensor detects an overload, it is determined that the platen has shifted position, and the platen is lowered to its lowest home position. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-91546 [Patent Document 2] Japanese Patent Publication No. 2020-121878 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the method disclosed in Patent Document 1 uses a camera as an imaging means and an imaging range changing means, resulting in a very expensive and complicated configuration.Also, the method disclosed in Patent Document 2 uses an encoder to detect the amount of movement and a dedicated sensor to detect overload, resulting in an expensive configuration. [Means for solving the problem]

[0009] In view of the above, an image reading device according to the present invention comprises: a loading table for loading manuscripts; a lifting means for lifting and lowering the loading platform; a take-in means for taking in the topmost document stacked on the stacking table; a side plate disposed opposite a side surface of the loading platform; a reflecting portion provided on one of a side surface of the loading platform and the side plate; a light reflective sensor provided on a side surface of the loading platform and the other of the side plates on which the reflecting portion is not provided; a height calculation means for calculating the height of the loading platform, The height calculation means calculates the height of the loading platform based on the light reception output value of the light reflection sensor. [Effects of the Invention]

[0010] According to the present invention, an image reading device can be provided that can grasp the height of the document table without lowering it to the lowest position, shorten the time it takes to move to an intermediate position, and grasp the descent of the document table due to overload. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view schematically illustrating the appearance of an image reading apparatus. [Figure 2] 1 is a cross-sectional view schematically showing the configuration of an image reading apparatus according to an embodiment of the present invention. [Figure 3] FIG. 1 is a schematic side view illustrating the configuration of a light reflective sensor. [Figure 4] FIG. 1 is a schematic top view illustrating the configuration of a light reflective sensor. [Figure 5] FIG. 2 is a front view showing the general configuration of a light reflective sensor; [Figure 6] FIG. 2 is a schematic diagram illustrating the configuration of a reflecting section in the first embodiment. [Figure 7] 4 is a flowchart showing the overall adjustment of the light reflective sensor according to the first embodiment. [Figure 8] 6 is a flowchart showing the process of moving the loading platform to the lowest position in the first embodiment. [Figure 9] 5 is a flowchart of white adjustment of the light reflective sensor according to the first embodiment. [Figure 10] 6 is a flowchart showing how the loading platform moves to the uppermost position in the first embodiment. [Figure 11] 5 is a flowchart of black adjustment of the light reflective sensor according to the first embodiment. [Figure 12]10 is a correlation graph between the height of the loading platform and the received light output value in the first embodiment. [Figure 13] 4 is a flowchart of a power-on process according to the first embodiment. [Figure 14] 6 is a flowchart showing the movement of the loading platform to an intermediate standby position in the first embodiment. [Figure 15] 10 is a flowchart of stacker control during feeding in the first embodiment. [Figure 16] FIG. 6 is a schematic diagram illustrating the configuration of a reflecting section according to a second embodiment. [Figure 17] 10 is a flowchart showing the overall adjustment of the light reflective sensor according to the second embodiment. [Figure 18] 10 is a flowchart illustrating the movement of the black adjustment position of the loading platform in the second embodiment. [Figure 19] 10 is a correlation graph between the height of the loading platform and the received light output value in the second embodiment. [Figure 20] FIG. 10 is a schematic diagram illustrating the configuration of a reflecting section according to a third embodiment. [Figure 21] 11 is a correlation graph between the height of the loading platform and the received light output value in the third embodiment. [Figure 22] FIG. 10 is a schematic front view illustrating a light reflective sensor and a reflecting portion according to a fourth embodiment. [Figure 23] FIG. 10 is a schematic front view illustrating the configuration of a reflecting section according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the present invention as defined in the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the present invention.

[0013] First Embodiment First, an original feeding device according to a first embodiment and an image reading device including the original feeding device will be described.

[0014] <Image reading device 200> Fig. 1 is a perspective view schematically showing the appearance of an image reading apparatus, Fig. 2 is a partial cross-sectional view schematically showing the configuration of an image reading apparatus including a document feeding device according to a first embodiment.

[0015] As shown in Figure 1, the positional relationship between the loading platform side surface 1b, which is the side surface of the loading platform 1, and the side plate 50 facing the loading platform side surface 1b is shown. The loading platform side surface 1b is hidden by the loading platform 1 and is therefore surrounded by a dotted line. The side plate 50 extends downward from the surface visible in Figure 1 and faces the loading platform side surface 1b.

[0016] 2, the image reading device 200 includes a sheet take-in device 150. A plurality of sheets (documents) F can be loaded (placed) on a loading table (document table) 1, which is configured to be freely raised and lowered. The loading table drive motor 2 is a stepping motor (pulse motor), and is rotationally driven by a drive pulse from a control unit 45 to raise and lower the loading table 1 as lifting means.

[0017] The control unit 45 counts the drive pulses, which are the drive resolution (smallest unit) of the motor, while driving the loading platform drive motor 2, and stores the count value as a pulse counter. When driving the loading platform drive motor 2 upward, the count is increased (the count is increased) in the positive direction, and when driving the loading platform drive motor 2 downward, the count is decreased (the count is decreased) in the negative direction.

[0018] The sheet intake position detection sensor 3 detects that the sheets loaded on the loading tray 1 are at the sheet intake position (a position where they can be taken in). If the sheets F loaded on the loading tray 1 are not at the sheet intake position, that is, if the sheet intake position detection sensor 3 does not detect the sheets F, the loading tray drive motor 2 is driven to move the loading tray 1 so that the top surface of the sheets is at the intake position.

[0019] The sheet stacking detection sensor 12 detects that the sheets F are stacked on the sheet stacking surface 1 a of the stacking table 1 .

[0020] The pickup roller 4 (take-in roller) acts as a take-in means and sequentially takes in sheets from the stacking table 1 and sends them to the feed roller 6. A pickup motor (not shown) rotates the pickup roller 4. In FIG. 2, the upper surface of the sheet is at the sheet take-in position, and if the pickup roller 4 is rotated, the take-in of the sheet F will begin.

[0021] The feed roller 6 is provided downstream of the pickup roller 4, and is driven by a feed motor 8 to rotate in a direction to feed the sheet F downstream in the conveying direction. The feed roller 6 is connected to the feed motor 8 via a one-way clutch, and the drive force of the feed motor 8 is transmitted in only one direction. When the sheet F is fed by the feed motor 8, the drive force is transmitted to the feed roller 6, but when the sheet F is conveyed by registration rollers 17, 18, etc. at a speed faster than the feed motor 8, the rotation of the feed motor 8 is not transmitted by the one-way clutch, and the feed roller 6 rotates following the conveyance of the sheet F.

[0022] A separation roller 7 is disposed opposite the feed roller 6 across the conveyance path and forms a nip with the feed roller 6. The feed roller 6 and the separation roller 7 constitute a pair of separation rollers 42, which functions as an example of a sheet separating section for separating and conveying the plurality of sheets F to be conveyed one by one.

[0023] In this embodiment, the separating force of the separation roller 7 on the sheet F can be changed. The sheet F can be separated simply by holding the separation motor 9 without rotating it. An even stronger separating force can be obtained by driving the separation motor 9 so that the separation roller 7 rotates in a direction returning the sheet F to the upstream side.

[0024] In this embodiment, the separation roller pair 42 is used, but a separation belt roller pair in which either the separation roller or the feed roller is a belt may be used instead of the separation roller pair 42. Also, the separation roller may be replaced with a separation pad that abuts against the sheet F to prevent multiple sheets F from being transported downstream.

[0025] Furthermore, by providing a double feed detection sensor 30 at a position where the separated sheets F pass, it is possible to detect whether the sheets F have been separated one by one by the sheet separating section. In this embodiment, a detection device using an ultrasonic transmitter / receiver is used as the double feed detection sensor 30, and double feed can be detected based on the amount of ultrasonic wave attenuation between the transmitter / receivers across the conveyance path.

[0026] The conveying motor 10 drives the registration roller 18 and conveying rollers 21 and 23 to convey the separated sheet F to an image reading position where the image on the sheet (original) F is read by image reading sensors 14 and 15 (image reading units), and further to a discharge position. By driving each roller, the opposing rollers (registration roller 17, conveying rollers 20 and 22) configured as a roller pair are driven, so that the sheet can be conveyed to the discharge position.

[0027] The conveying motor 10 also drives each roller so that the conveying speed can be changed according to settings such as the optimum speed for reading the sheet F and the resolution of the sheet F. A resist clutch (not shown) transmits the rotational driving force of the conveying motor 10 to the resist rollers 18 (document conveying section) or blocks the transmission, thereby driving the resist rollers 18 or stopping the driving thereof.

[0028] The nip gap adjustment motor 11 adjusts the gap between the feed roller 6 and the separation roller 7, or the pressure force with which the feed roller 6 is pressed against the separation roller 7 via the sheet. This adjusts the gap or pressure force to suit the thickness of the sheet F, allowing the sheet F to be separated.

[0029] A pair of conveying rollers consisting of conveying rollers 20 and 21, a pair of conveying rollers consisting of conveying rollers 22 and 23, and a pair of rollers further downstream shown in FIG.

[0030] The image reading device 200 includes a control unit 45 that controls the overall operation of the device. The control unit 45 is configured, for example, by one or more processors (CPUs).

[0031] <Reflector 70 and Light Reflective Sensor 60> Next, the reflecting section 70 and the light reflective sensor 60 provided on the side surface 1b of the loading platform will be described. When the loading platform 1 moves up and down, the reflecting section 70 also moves up and down. The light reflective sensor 60 is provided on the side plate 50.

[0032] 3 is a schematic diagram showing the configuration of the light reflective sensor 60, and is a side view (viewing the light reflective sensor 60 from the reflector 70) of the image reading device 200 from the direction of FIG. 2. The slit 64 narrows the detection range both in the vertical direction (the height direction of the device, which is perpendicular to the conveying direction) and in the conveying direction.

[0033] FIG. 4 is a schematic diagram showing the configuration of the light reflective sensor 60, and is a top view of the image reading device 200.

[0034] The light reflective sensor 60 is composed of a light emitting section 61, a light receiving section 62, a partition plate 63, and a slit 64. Hereinafter, when the light reflective sensor 60 is referred to, it will collectively refer to the light emitting section 61, the light receiving section 62, the partition plate 63, and the slit 64.

[0035] The light-emitting unit 61 is a light-emitting element such as an LED that emits infrared light. It irradiates the infrared light toward the reflecting unit 70 provided on the loading platform 1. The light-receiving unit 62 is a light-receiving element such as a phototransistor that has sensitivity to receiving infrared light. The infrared light irradiated by the light-emitting unit 61 is reflected by the reflecting unit 70, and the reflected light is received by the light-receiving unit 62. A light-receiving signal (voltage) proportional to the amount of received light is output, and is detected by the control unit 45.

[0036] The partition plate 63 is provided to block direct light, which is infrared light emitted by the light-emitting portion 61 and which would otherwise reach the light-receiving portion 62 directly.

[0037] The slit 64 is an opening formed by the cover member 65 of the light reflective sensor 60. The reason for providing the slit 64 is to narrow the detection range of the light reflective sensor 60, i.e., the irradiation range of the light-emitting unit 61 and the light-receiving range of the light-receiving unit 62. The slit 64 narrows the width of the detection range 66 (width in a direction parallel to the conveying direction), blocking reflected light from areas other than the reflecting unit 70. However, if the width of the detection range 66 is narrower than that of the reflecting unit 70, the reflecting unit 70 cannot be detected, so the width of the detection range 66 needs to be equal to or greater than the width of the reflecting unit 70 (width in a direction parallel to the conveying direction).

[0038] A detection range 66 indicates the detection range of the light reflective sensor 60. A slit 64 is formed so that the detection range 66 falls within the reflecting portion 70.

[0039] The reflecting portion 70 is disposed so as to face the light reflection type sensor 60, and is provided on the side surface 1b of the loading platform 1.

[0040] The partition plate 63 and cover member 65 are preferably made of an opaque material so as to make it difficult for infrared light to pass through. It is even better to make them of a material such as a dark-colored resin to prevent reflection on the surface. Alternatively, they may be made of metal, with an anti-reflection coating or additional material applied to the surface to prevent reflection of infrared light.

[0041] FIG. 5 is a schematic diagram showing the configuration of the light reflective sensor 60, as seen from the front (upstream side in the conveying direction) of the image reading device 200.

[0042] The slit 64 narrows the detection range 66 in the vertical direction of the device, and because the reflectivity of the reflecting section 70 (described later) changes in the vertical direction, this change can be accurately detected by the light reflective sensor 60. The side of the loading platform 1 is approximately vertical, and the distance between the light reflective sensor 60 and the reflecting section 70 remains approximately constant even when the loading platform 1 is raised or lowered.

[0043] FIG. 6 is a schematic diagram illustrating the configuration of the reflecting section 70. As shown in FIG.

[0044] The reflective section 70 is composed of, from top to bottom, a white section 71 (region with maximum reflectivity), a varying section 72, and a black section 73 (region with minimum reflectivity). The loading platform 1 can be moved to the lowest position regardless of whether a sheet F is loaded or not, but cannot be moved to the highest position if a sheet F is loaded. For this reason, the white section 71 used for white adjustment, which will be described later, should be located in a position that falls within the detection range 66 when the loading platform 1 is in the lowest position, i.e., above the reflective section 70. The white section 71 is the region with maximum reflectivity, and the black section 73 is the region with minimum reflectivity.

[0045] Arrow A indicates the height position of the light reflective sensor 60 when the loading platform 1 is at its lowest position. Because the reflective portion 70 is also lowered along with the loading platform 1, the upper part of the reflective portion 70, i.e., the white portion 71, falls within the detection range 66. Arrow B is an example of the height position of the light reflective sensor 60 when the changing portion 72 shown in FIG. 6 falls within the detection range 66, particularly when the loading platform 1 is at the intermediate position. Arrow C indicates the height position of the light reflective sensor 60 when the loading platform 1 is at its highest position, and the lower part of the reflective portion 70, i.e., the black portion 73, falls within the detection range 66.

[0046] By configuring the reflecting section 70 and the light reflective sensor 60 in this way, the reflectivity of the reflecting section 70 is maximum when the loading platform 1 is at the lowest position, and the reflectivity decreases as the loading platform 1 rises, reaching a minimum when the loading platform 1 is at the highest position. Therefore, it can be seen that the greater the amount of light received by the light reflective sensor 60, i.e., the greater the light reception output value, the lower the loading platform 1 is, and the less the amount of light received, i.e., the smaller the light reception output value, the higher the loading platform 1 is.

[0047] In the present invention, the light reflective sensor is adjusted by the control unit 45 as height calculation means for calculating the height of the loading platform 1. This is done in the order of white adjustment (maximum value adjustment, dimming) and black adjustment (minimum value adjustment). White adjustment is the adjustment of the light emission amount so that the light receiving output value when the white part 71 is in the detection range 66 (when the loading platform 1 is at the lowest position) becomes the expected light receiving output value (white adjustment target value), which is a specified output. Black adjustment is the measurement of the light receiving output value when the black part 73 is in the detection range 66 (when the loading platform 1 is at the highest position) using the white-adjusted light emission amount.

[0048] The present invention is configured with white and black, but it is not necessary that the white portion 71 is white and the black portion 73 is black; it is sufficient that the reflectance of the changing portion 72 changes constantly, and the reflectance is higher the closer to the white portion 71 and lower the closer to the black portion 73.

[0049] Furthermore, the reflecting portion 70 is not limited to the above-described form. It may be formed by printing black and white on the side surface of the loading platform 1, or a separate sticker-like material may be attached. A glossy finish may be used instead of white, or a recess may be used instead of black. The recess may be formed with a hole to prevent light reflection, or may be tilted with respect to the optical axis of the irradiated light to prevent reflected light from being reflected back to the light receiving portion 62. Furthermore, while the shape of the varying portion 72 is illustrated as a right triangle, it may also be an isosceles triangle or a pattern combining multiple shapes. The color density of the varying portion 72 may be changed in the height direction, or the black and white ratio of the halftone dot pattern may be changed.

[0050] <Adjustment flow of the light reflective sensor 60> The adjustment flow of the light reflective sensor 60 will be described with reference to FIGS.

[0051] 7, the control unit 45 causes the light-emitting unit 61 to emit light at an initial light emission amount (S101), and then lowers the loading platform 1 to the lowest position (S102). The initial light emission amount is a light amount that does not cause the light-receiving output value of the light-receiving unit 62 to become saturated.

[0052] The movement of the loading platform 1 to the lowest position (S102) will be described below with reference to the flowchart of FIG.

[0053] The control unit 45 drives the loading platform drive motor 2 to lower the loading platform 1 (S201), and determines whether the light-receiving output value increases (S202). If the light-receiving output value increases (YES in S202), it determines that the loading platform 1 has not yet reached the lowest position, and continues to lower the loading platform 1.

[0054] If the light receiving output value no longer increases (NO in S202), the white part 71 of the reflecting part 70 falls within the detection range 66 at the lowest position, and therefore the light receiving output value no longer increases. Therefore, it is determined that the loading platform 1 has reached the lowest position, and the loading platform drive motor 2 is stopped to stop the descent of the loading platform 1 (S203).

[0055] After the lowering of the loading platform 1 is stopped (S203), white adjustment is performed (S103). The white adjustment (S103) is performed as shown in the flowchart of FIG.

[0056] The control unit 45 checks whether the received light output value matches the white adjustment target value (S301), and if so (S301: YES), ends the white adjustment. If they do not match (S301: NO), it checks whether the received light output value is greater than the white adjustment target value (S302), and if so (S302: YES), it reduces the amount of light emitted (S303), and if so (S302: NO), it increases the amount of light emitted (S304). Thereafter, it checks again whether the received light output value matches the white adjustment target value (S305). If they do not match (S305: NO), it returns to step S303 and continues the white adjustment, and if they match (S305: YES), it ends the white adjustment.

[0057] If the amount of light emitted by the light-emitting unit 61 is too great, the light-receiving output value of the light-receiving unit 62 may become saturated, and the light-receiving output value may not change as the loading platform 1 approaches the lowest position, resulting in a false detection that the platform is at the lowest position. By performing white adjustment, this saturation of the light-receiving output value can be avoided, and false detection of the lowest position can be prevented. Also, if the amount of light emitted by the light-emitting unit 61 is too small, the change in the light-receiving output value of the light-receiving unit 62 may be small even when the loading platform 1 is raised or lowered, resulting in a poor resolution; however, by performing white adjustment, the resolution can be improved.

[0058] After the white adjustment (S103) is completed, the loading platform 1 is raised and moved to the uppermost position (S104). The process for moving to the uppermost position (S104) is as shown in the flowchart of FIG.

[0059] The control unit 45 drives the stacker drive motor 2 to raise the stacker 1 (S401), and checks whether the sheet F is in the take-in position using the sheet take-in position detection sensor 3 (S402). If the sheet F is in the take-in position (YES in S402), the control unit 45 stops raising the stacker 1 (S405), and ends the raising operation of the stacker 1. If the sheet F is not in the take-in position (NO in S402), the control unit 45 checks whether the light-receiving output value is decreasing (S403). If the light-receiving output value is decreasing (YES in S403), it is determined that the stacker 1 has not reached the uppermost position, and the process returns to step S402 to continue raising the stacker 1. If the light-receiving output value no longer decreases (NO in S403), it is determined that the stacker 1 has reached the uppermost position, and the control unit 45 sets the uppermost position movement completion flag (S404).

[0060] After the top position movement completion flag is set (S404), the loading platform drive motor 2 is stopped, and the lifting of the loading platform 1 is stopped (S405), thereby completing the lifting of the loading platform 1. At the top position, the black part 73 of the reflecting part 70 is within the detection range 66, and therefore the received light output value stops decreasing.

[0061] After the loading platform 1 is raised to the uppermost position (S104), black adjustment is performed (S105).

[0062] The black adjustment is performed as shown in the flowchart in FIG.

[0063] The top position movement completion flag is checked (S501), and if it is set (S501: YES), it is determined that the stacker 1 is at the top position, and the control unit 45 holds the received light output value as the result of black adjustment (S502). Thereafter, the top position movement completion flag is cleared (S503), and the black adjustment completion flag is set (S504), thereby completing the black adjustment.

[0064] If it is determined in step S501 that the top position movement completion flag is not set (S501: NO), the loading platform 1 is not in the top position, so the black portion 73 is not within the detection range 66, and it is determined that black adjustment cannot be performed. Thereafter, as simple black adjustment, the control unit 45 turns off the light-emitting unit 61 (S505) and holds the received light output value as the result of black adjustment (S506). After holding the received light output value (S506), the control unit 45 turns on the light-emitting unit 61 again with the light amount resulting from the white adjustment (S507), clears the simple black adjustment completion flag (S508), and ends the black adjustment.

[0065] After the black adjustment (S105) is completed through the above process, the adjustment of the light reflective sensor 60 itself is completed.

[0066] Ideally, the black portion 73 does not reflect light and therefore does not produce a light receiving output value, but in reality, some reflection occurs, and there is a possibility that a certain output will be produced from the light receiving portion 62 due to reflection around the slit 64, dark current of the light receiving portion 62, etc. In this case, checking the light receiving output value when there is a black portion 73 opposite and using it as the result of black adjustment will lead to accurate calculation of the height of the loading platform 1.

[0067] 12 (S505 to S508), the effect of dark current on the received light output value can be measured, and a certain level of black adjustment effect can be obtained. Furthermore, by clearing the black adjustment completion flag (S508) after performing the simple black adjustment, it becomes easy to re-perform the black adjustment (S502 to S504) later.

[0068] If it is known that the influence of reflections in the black portion 73 and around the slit 64 is very small, the raising of the loading platform 1 (S104) shown in FIG. 8 may be omitted, and simple black adjustment (S505 to S508) may be performed in the black adjustment (S105) process, thereby reducing the adjustment time.

[0069] <How to calculate the height of loading platform 1> FIG. 12 is a graph showing the correlation between the height of the loading platform 1 and the received light output value.

[0070] The horizontal axis of the graph represents the height of the position of the loading platform 1, and the vertical axis represents the light-receiving output value. As the loading platform 1 is lowered, the position at which the light-receiving output value stops increasing is the lowest position of the loading platform 1. As the loading platform 1 is raised, the position at which the light-receiving output value stops decreasing is the highest position. Between the lowest and highest positions, that is, at the change section 72, the light-receiving output value and the height of the loading platform 1 correspond and are correlated in terms of reflectivity, and the height of the loading platform 1 can be calculated from the light-receiving output value.

[0071] A method for calculating the height of the loading platform 1 by the height calculation means based on the received light output value will be described.

[0072] As shown in Figure 12, the received light output value when the loading platform 1 is in the lowest position is set to 1050, and since the received light output value at the lowest position corresponds to the white part 71, it is the same as the white adjustment target value. The received light output value when the loading platform 1 is in the highest position is set to 50, and since the received light output value at the highest position corresponds to the black part 73, it is the value of the black adjustment result. Therefore, if the current received light output value is set to L1 and the height of the loading platform 1 is set to a percentage from the lower limit position as H1, the following equation can be derived.

[0073] H1 [%] = ((White adjustment target value - L1) / (White adjustment target value - Black adjustment value)) x 100

[0074] In this way, the control unit 45 can calculate the height of the loading platform 1 from the received light output value using the above formula.

[0075] <Moving loading platform 1 to intermediate standby position> Next, we will explain how to set the standby height of the stacking tray 1. The user can select and set the standby position of the stacking tray 1 from multiple options depending on the number of sheets F to be stacked. If the user wants to stack the maximum possible amount of sheets F, set the lowest position as the standby position of the stacking tray 1.

[0076] On the other hand, if it is desired to stack only a small number of sheets F, an intermediate position set above the lowest position is set as the standby position of the stacker 1. If a position where a predetermined number of sheets, for example, 100 or 300 sheets, can be stacked is set as the intermediate standby position, then a 100-sheet stacking position or a 300-sheet stacking position is set as the intermediate standby position. The user can select one of these standby positions: 100, 300, or 500 sheets. If the standby position selected by the user is the intermediate standby position, which is the 100-sheet or 300-sheet stacking position, the stacker drive motor 2 is driven, and the stacker 1 moves to a height of the stacker 1 corresponding to the light reception output value of the light reflective sensor 60.

[0077] <Flow of moving the loading platform to the intermediate waiting position> The operation of the loading platform 1 from when the image reading device 200 is turned on until it moves to the intermediate standby position and waits there will be described with reference to the flowcharts of FIGS.

[0078] When the image reading device 200 is powered on, the light reflective sensor 60 is dimmed (S601) as shown in Fig. 13. The process of dimming the light reflective sensor 60 (S601) is the same as the flowchart shown in Fig. 7 above, and therefore a description thereof will be omitted.

[0079] After adjusting the light intensity of the light reflective sensor 60 (S601), it is confirmed whether the standby position of the loading platform 1 set by the user is the lowest position or the intermediate position (S602). If the setting is the intermediate standby position (S602: YES), the loading platform 1 is moved to the intermediate standby position (S603), as described below, and the process ends. If the setting is the lowest position (S602: NO), the loading platform 1 is moved to the lowest position (S604), and the process ends. The movement to the lowest position (S604) has been explained in FIG. 8 above, so a detailed explanation is omitted.

[0080] The operation of moving to the intermediate standby position (S603) will be described with reference to the flowchart shown in FIG.

[0081] To determine whether the loading platform 1 is already at the intermediate position, the light receiving output value corresponding to the intermediate position is compared with the light receiving output value at the current position (S701). If the light receiving output value at the current position matches the light receiving output value (intermediate value) at the intermediate position (S701: YES), it is determined that the loading platform 1 is at the intermediate position, and the process ends.

[0082] If the light receiving output value at the current position does not match the light receiving output value at the intermediate position (S701: NO), it is determined whether the light receiving output value at the current position is above or below the intermediate value (S702). If the light receiving output value at the current position is smaller than the intermediate value (S702: YES), it is determined that the loading platform 1 is above the intermediate position, and the loading platform 1 begins to descend (S703). If the light receiving output value is larger than the intermediate value (S702: NO), it is determined that the loading platform 1 is below the intermediate position, and the loading platform 1 begins to ascend (S704).

[0083] Thereafter, as the loading platform drive motor 2 is driven, it is determined whether the light receiving output value at the current position matches the intermediate value (S705). If they do not match (S705: NO), it is determined that the loading platform 1 has not yet reached the intermediate position, and driving continues until they match (S706). If the light receiving output value at the current position matches the intermediate value (YES in S705), the operation of the loading platform 1 is stopped (S707), and the process of moving to the intermediate standby position is completed. With the above process, the process when the power is turned on for the image reading device 200 shown in FIG. 13 is completed.

[0084] <Operation flow of the loading platform during feeding> Next, the operation of the stacking table 1 when feeding sheets and reading images by user operation will be described with reference to the flowchart shown in FIG.

[0085] When the image reading device 200 is in a standby state, the user loads sheets F on the loading tray 1. At that time, it is determined whether or not a feeding start instruction has been issued (S801), and if there is no feeding start instruction (S801: NO), the device waits until a feeding instruction is issued (S802).

[0086] If there is a feeding start instruction (S801: YES), it is confirmed whether the sheet F to be fed is present on the stacking tray 1 (S803). If no sheet F is detected on the stacking tray 1 (S803: NO), the feeding start instruction is canceled, and the sheet F is stacked on the stacking tray 1, and the system waits until another feeding start instruction is given (S802). If the presence of sheet F on the stacking tray 1 is detected (S803: YES), the stacking tray 1 is raised (S804) and it is determined whether or not there is a sheet F at the intake position (S805). If the sheet intake position detection sensor 3 does not detect a sheet F at the intake position (S805: NO), the stacking tray 1 continues to rise until it is detected. If a sheet F is detected at the intake position (S805: YES), the raising of the stacking tray 1 is stopped (S806).

[0087] After the rising of the stacking tray 1 is stopped (S806), the feeding of the sheets F is started (S807), and the sheets F stacked on the stacking tray 1 are fed one after another. After that, the operation of the stacking tray 1 is controlled as described below so that the top surface of the sheets F on the stacking tray 1 and the intake position always coincide with each other.

[0088] After feeding starts (S807), the sheet intake position detection sensor 3 detects and determines whether or not a sheet F is present at the intake position (S808). If a sheet F is detected at the intake position (S808: YES), it is determined whether the stacking tray 1 is in operation (S809). If the stacking tray 1 is in operation (S809: YES), it stops (S810), and if it is not in operation (S809: NO), the process proceeds to step S814, which will be described later.

[0089] If sheet F is not detected (S808: NO), it is checked whether the stacking tray 1 is lowered (S811). This takes into consideration the possibility that the stacking tray 1 has been overloaded and lowered, and the determination is made based on whether the light-receiving output value has increased. For example, when the relationship between the light-receiving output value and the height of the stacking tray 1 is as shown in FIG. 12, to detect that the height of the stacking tray 1 has lowered by 10%, it is checked whether the light-receiving output value has increased by 100.

[0090] If the stacking tray 1 has been lowered (S811: YES), the feeding of the sheets F is temporarily stopped (S812), and the stacking tray 1 is raised again (S804) to resume sheet feeding. If the stacking tray 1 has not been lowered (S811: NO), the stacking tray 1 continues to be raised (S813) to continue sheet feeding. Thereafter, the sheet stacking detection sensor 12 checks whether the sheets F are stacked on the stacking tray 1 (S814), and if stacking is detected (S814: YES), the process returns to step S808 to continue the feeding. If stacking of the sheets F is not detected (S814: NO), the stacking tray 1 is stopped (S815).

[0091] After the loading platform 1 has stopped (S815), it is checked whether the black adjustment completed flag is set (S816). If the flag is set (S816: YES), the standby position setting is checked (S819). If the flag is not set (S816: NO), the loading platform 1 is moved to the uppermost position to redo the black adjustment (S817), and the black adjustment is then performed (S818). Thereafter, the standby position setting is checked (S819). The movement to the uppermost position (S817) and the black adjustment (S818) have been described above, so a description thereof will be omitted.

[0092] If the standby position setting is not the intermediate position (S819: NO), the loading platform 1 moves to the lowest position (S820), and if the standby position setting is the intermediate position (S819: YES), the loading platform 1 moves to the intermediate standby position (S821). When the movement of the loading platform 1 is completed in each process, the process ends.

[0093] If it is determined in step S811 that the loading platform 1 is lowering, the user may be notified that there is an abnormality in the position of the loading platform 1, and in an image reading device equipped with a display unit or a buzzer, the user may be notified by displaying an abnormality in the loading platform 1 on the display unit or sounding the buzzer. If the user overloads the loading platform 1, there is a possibility that the user may overload it repeatedly without realizing it, which could result in damage to the device. If the user is notified and warned, the frequency of overloading can be reduced, preventing damage to the device.

[0094] In addition, the following configuration and control may be added to assist in controlling the position of the loading platform.

[0095] For example, the loading platform 1 is provided with a home position detection sensor 13 arranged at the lowest position within the movable range of the lifting operation, and the control unit 45 detects that the loading platform 1 is at the home position based on the detection result of the home position detection sensor 13. In particular, since the loading platform 1 is often at the lowest position when the power is ON, by providing the home position detection sensor 13, it is possible to detect that the loading platform 1 is at the lowest position without moving it, thereby reducing the movement time.

[0096] In this embodiment, as shown in Figure 2, the reflecting unit 70 is arranged on the side surface 1b of the loading platform, and the light-reflecting sensor 60 is arranged on the side panel 50, but it is also possible to arrange the light-reflecting sensor 60 on the side surface 1b of the loading platform, and the reflecting unit 70 on the side panel 50.

[0097] As described above, by performing processing using the reflecting unit 70 having the shape shown in Figure 6, it is possible to quickly and accurately determine the height of the loading platform 1 at an intermediate position without lowering the loading platform 1 to the lowest position, thereby shortening the time required to move to the intermediate height and instantly detecting unintentional movement of the loading platform 1 due to overload, making it possible to provide a configuration at an inexpensive cost.

[0098] <Second embodiment> Next, a document feeder according to a second embodiment and an image reading apparatus including the document feeder will be described. Note that a description of parts common to the first embodiment will be omitted, and differences from the first embodiment will be mainly described.

[0099] In this embodiment, a reflecting section 80 is used. FIG.

[0100] 16 is configured in this order from top to bottom: a white section 81 (region with maximum reflectance), a black section 82 (region with minimum reflectance), and a variable section 83. By configuring them in this order, when adjusting the light reflective sensor 60, the loading platform 1 can be moved to the black adjustment position, i.e., the black section 82, simply by lifting it slightly from the lowest position, thereby reducing the adjustment time. The variable section 83 is configured so that the reflectance increases as the loading platform 1 is raised from the black section 82. By making the reflectance lower when the loading platform 1 is moved to the highest position than that of the white section 81, it is possible to distinguish between the highest position and the lowest position (the position of the white section 81).

[0101] Arrow A indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the lowest position. The upper part of the reflective portion 80, i.e., the white portion 81, falls within the detection range 66. Arrow B indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the black adjustment position, which is slightly raised from the lowest position, and the black portion 82 falls within the detection range 66. Arrow C indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the highest position, and the detection range 66 includes the lower part of the reflective portion 70, i.e., the position where the reflectance is maximum in the changing portion 83.

[0102] FIG. 17 is a flow chart showing the adjustment process of the light reflective sensor 60.

[0103] The adjustment process of the light reflective sensor 60 is the same as the adjustment process in the first embodiment described above, and after white adjustment (S103), the loading platform 1 is moved to the black adjustment position (S1004). The subsequent processes are the same as those in the first embodiment described above.

[0104] The process of moving the loading platform 1 to the black adjustment position (S1004) is as shown in the flowchart of FIG.

[0105] The process of moving the loading platform 1 to the black adjustment position (S1004) is performed in the same manner as in the first embodiment described above, and it is confirmed whether the light receiving output value is decreasing (S4003). If it is determined that the light receiving output value is no longer decreasing (S4003: NO), it is determined that the movement of the loading platform 1 to the black adjustment position is completed, and a black adjustment position movement completion flag is set (S4004). The subsequent process is the same as in the first embodiment described above.

[0106] In this embodiment, by using the reflecting portion 80, the loading tray 1 can reach the black adjustment position by simply lifting it a small amount from the lowest position, so black adjustment can be performed in a short time without lifting the loading tray to the highest position. Also, even if sheets F are loaded on the loading tray 1, if the number of sheets in the stack is not large, the loading tray 1 can be moved to the black adjustment position and black adjustment can be completed.

[0107] FIG. 19 is a graph showing the correlation between the height of the loading platform 1 and the received light output value.

[0108] When the loading platform 1 is at the lowest position, the received light output value corresponds to the white portion 81, and when it is slightly raised to the black adjustment position, the received light output value corresponds to the black portion 82. Between the lowest position and the black adjustment position, the received light output value and the height of the loading platform 1 are correlated and decrease rapidly. Between the lowest position and the highest position within the changing portion 83, the received light output value and the height of the loading platform 1 are correlated as the reflectance of the changing portion 83 and increase.

[0109] Based on the received light output value, a height candidate for the loading platform 1 is calculated by the height calculation means described in the first embodiment. In this embodiment, since there are multiple heights (two heights) for the same received light output value as shown in Fig. 19, the calculation result by the height calculation means becomes a "height candidate."

[0110] In this embodiment, even if the height of the loading platform 1 does not correspond to the light receiving output value as described above, the height of the loading platform 1 can be calculated from height candidates based on the magnitude of the change in the light receiving output value when the loading platform 1 is raised and lowered by the loading platform drive motor 2, and if the change is large, it can be determined that the loading platform 1 is between the lowest position and the black adjustment position, and if the change is small, it can be determined that it is in the area of ​​the change section 83.

[0111] As described above, in the second embodiment, by performing processing using the reflecting section 80 having the shape shown in FIG. 16, the amount of lifting and lowering of the loading table 1 required for black correction can be reduced, and the adjustment time can be shortened.

[0112] <Third embodiment> Next, a document feeder according to a third embodiment and an image reading apparatus including the document feeder will be described. Note that a description of parts common to the first and second embodiments will be omitted, and differences from the first and second embodiments will be mainly described.

[0113] In this embodiment, a reflecting section 90 is used. FIG.

[0114] 20 is configured in the following order from top to bottom: upper white portion 91 (region of maximum reflectance), upper black portion 92 (region of minimum reflectance), upper varying portion 93, middle white portion 94 (region of maximum reflectance), lower varying portion 95, lower black portion 96 (region of minimum reflectance), and lower white portion 97 (region of maximum reflectance). By configuring them in this order, the reflective portion 90 has multiple white portions, namely, upper white portion 91, middle white portion 94, and lower white portion 97, making it possible to clearly distinguish the top position, middle position, and bottom position.

[0115] Since the position where the height needs to be clearly distinguished is the center, the middle white portion 94 is provided in the center in the height direction. The middle white portion 94 may be positioned above or below depending on the position where the height needs to be clearly distinguished. The upper white portion 91, middle white portion 94, and lower white portion 97 all have the same reflectance, and the upper black portion 92 and lower black portion 96 also have the same reflectance.

[0116] In this embodiment, white adjustment can be performed whether the height of the loading platform 1 is at the top, middle, or bottom position. Black adjustment can also be performed at either the upper black adjustment position, which is slightly elevated from the bottom position, or the lower black adjustment position, which is slightly lowered from the top position. This reduces the time it takes to raise and lower the loading platform 1 to adjust the light reflective sensor 60.

[0117] Arrow A indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the lowest position. The upper part of the reflective portion 90, i.e., the upper white portion 91, falls within the detection range 66. Arrow B indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the lower black adjustment position, slightly raised from the lowest position, and the upper black portion 92 falls within the detection range 66. Arrow C indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the intermediate position, and the intermediate white portion 94 falls within the detection range 66. Arrow D indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the upper black adjustment position, slightly lower than the highest position, and the lower black portion 96 falls within the detection range 66. Arrow E indicates the height position of the light reflective sensor 60 when the loading platform 1 is in the uppermost position, and the lower white portion 97 falls within the detection range 66.

[0118] The dimming flow of the light reflective sensor 60 can be the same as that of the second embodiment, as shown in Fig. 17. In this case, the loading platform 1 uses the lower limit position (the position of arrow A in Fig. 20) for white adjustment, and the lower black adjustment position (the position of arrow B in Fig. 20) slightly elevated from the lower limit position is used for black adjustment. If the loading platform 1 uses the intermediate position (the position of arrow C in Fig. 20) or the upper limit position (the position of arrow E in Fig. 20) for white adjustment, or if the loading platform 1 uses the upper black adjustment position (the position of arrow D in Fig. 20) slightly elevated from the upper limit position for black adjustment, the lifting direction (S102, S1004) of the loading platform 1 in the dimming flow (Fig. 17) can be changed appropriately.

[0119] FIG. 21 is a graph showing the correlation between the height of the loading platform 1 and the received light output value.

[0120] When the loading platform 1 is at the lowest position, the received light output value corresponds to the upper white portion 91 of the reflective portion 90, and when it rises slightly to the lower black adjustment position, the received light output value corresponds to the upper black portion 92. When it is between the lower black adjustment position and the intermediate position, the received light output value corresponds to the upper varying portion 93, and the received light output value and the height of the loading platform 1 correlate as the reflectivity of the upper varying portion 93, and rise.

[0121] When it is in the intermediate position, the received light output value corresponds to the intermediate white portion 94. When it is between the intermediate position and the upper black adjustment position, the received light output value corresponds to the lower varying portion 95, and the received light output value and the height of the loading platform 1 correlate as the reflectance of the lower varying portion 95, and decrease. When it is in the upper black adjustment position, the received light output value corresponds to the lower black portion 96, and when it is slightly raised to the uppermost position, the received light output value correlates to the lower white portion 97.

[0122] The difference from the first and second embodiments is that there are multiple white portions, black portions, and variable portions. Therefore, the height of the loading platform 1 does not correspond to the light-receiving output value as described above. Even if the height of the loading platform 1 does not correspond to the light-receiving output value, as in the second embodiment described above, the height of the loading platform 1 can be calculated from height candidates based on changes in the light-receiving output value (change information) when the loading platform 1 is raised or lowered by the loading platform drive motor 2, and it is possible to determine the height of the loading platform 1, such as whether the loading platform 1 is between the lowest position and the intermediate position, or between the intermediate position and the highest position.

[0123] In addition, the vertical widths of the upper white portion 91, the middle white portion 94, and the lower white portion 97 may be changed to make them easier to distinguish from the change in the light receiving output value when the loading platform 1 is raised and lowered by a small amount, and similarly, the vertical widths of the upper black portion 92 and the lower black portion 96 may each be changed to make them easier to distinguish.

[0124] As described above, by performing processing using the reflecting portion 90 having the shape shown in FIG. 20, the top position, middle position, and bottom position can be clearly distinguished, and the amount of lifting and lowering of the loading platform 1 required for white adjustment and black adjustment can be reduced, thereby shortening the adjustment time.

[0125] <Fourth embodiment> An original feeding device and an image reading device including the original feeding device according to the fourth embodiment will be described. Note that a description of parts common to the first to third embodiments will be omitted, and differences will be mainly described.

[0126] This embodiment uses a reflecting section 100. Figure 22 is a schematic front view showing the general configuration of the reflecting section 100.

[0127] In this embodiment, the side surface 1b of the loading platform has a sloped shape as shown in Fig. 22. By arranging the reflector 100 on the sloped surface, the distance between the reflector 100 and the light reflective sensor 60 changes as the loading platform 1 rises and falls, so that the reflectance of the reflector 100 can be changed depending on the distance.

[0128] FIG. 23 is a schematic front view showing the general configuration of the reflecting section 80. As shown in FIG.

[0129] 23, the reflective section 100 is configured in this order from top to bottom: a short-distance section (region with maximum reflectance) 101, a changing section 102, and a long-distance section (region with minimum reflectance) 103. The region closest to the reflective section 100 and the light reflective sensor 60 is the short-distance section 101, the region farthest from the reflective section 100 is the long-distance section 103, and the region between them is the changing section 102.

[0130] Arrow A indicates the height position of the light reflective sensor 60 when the loading platform 1 is at the lowest position. The upper part of the reflecting section 100, i.e., the short-distance section 101, falls within the detection range 66. Arrow B indicates the height position of the light reflective sensor 60 when the loading platform 1 is at the intermediate position, and the changing section 102 falls within the detection range 66. Arrow C indicates the height position of the light reflective sensor 60 when the loading platform 1 is at the highest position, and the lower part of the reflecting section 100, i.e., the long-distance section 103, falls within the detection range 66.

[0131] As a result, the inclined surface of the side surface 1b of the loading platform can be used as the reflecting portion 100, thereby simplifying the structure. The relationship between the received light output value and the height of the loading platform 1 is the same as in the first embodiment (FIG. 12), and various flowcharts are also the same as in the first embodiment. [Explanation of symbols]

[0132] F seat 1 Loading platform 1a Sheet loading surface 1b Side of loading platform 2 Loading platform drive motor 3 Sheet intake position detection sensor 4 Pickup roller 6 Feeding roller 7 Separation roller 8 Feeding motor 9 Separation motor 10. Transport motor 11 Nip gap adjustment motor 12 Sheet stacking detection sensor 13 Platform position detection sensor 14, 15 Image reading sensor 42 Separation roller pair 45 Control Unit 50 Side panel 60 Light reflective sensor 61 Light-emitting part 62 Light receiving part 63 Divider 64 Slit 65 Cover member 66 Detection range 70 Reflector 71 Shirabe 72 Changes 73 Kurobe 80 Reflector 81 Shirabe 82 Kurobe 83 Changes 90 Reflector 91 Upper white part 92 Upper Kurobe 93 Upper transition section 94 Intermediate white part 95 Lower Change 96 Shimo Kurobe 97 Lower white part 100 Reflector 101 Near distance section 102 Changes 103 Long distance section 150 Sheet intake device 200 Image reader

Claims

1. a loading table for loading manuscripts; a lifting means for lifting and lowering the loading platform; a take-in means for taking in the topmost document stacked on the stacking table; a side plate disposed opposite a side surface of the loading platform; a reflecting portion provided on one of the side surface of the loading platform and the side plate; a light reflective sensor provided on a side surface of the loading platform and the other of the side plates on which the reflecting portion is not provided; a height calculation means for calculating the height of the loading platform, The image reading device is characterized in that the height calculation means calculates the height of the loading platform based on a light reception output value from the light reflection sensor.

2. 2. The image reading device according to claim 1, wherein the reflective portion has a maximum reflectance region, a minimum reflectance region, and a varying portion, and the reflectance varies in the height direction, with the maximum reflectance region, the varying portion, and the minimum reflectance region being adjacent in that order.

3. 2. The image reading device according to claim 1, wherein the reflective portion has a maximum reflectance region, a minimum reflectance region, and a changing portion, the reflectance of which changes in the height direction, and the maximum reflectance region and the minimum reflectance region are adjacent to each other.

4. 2. The image reading device according to claim 1, wherein the reflective portion has a maximum reflectance region, a minimum reflectance region, and a change portion, and the reflectance changes in the height direction, and the reflective portion has a plurality of the maximum reflectance regions, the minimum reflectance regions, and the change portion.

5. 3. The image reading device according to claim 2, wherein the height calculation means adjusts the maximum value of the light reflective sensor in the maximum reflectance region of the reflecting section and adjusts the minimum value of the reflective sensor in the minimum reflectance region of the reflecting section, and calculates the height of the loading platform by comparing the current light receiving output value with an expected light receiving output value, which is a specified output.

6. 5. The image reading device according to claim 3, wherein the height calculation means calculates a candidate height for the loading platform by comparing a current light receiving output value with an expected light receiving output value, which is a specified output, and calculates the height of the loading platform based on a change in the light receiving output value when the loading platform is raised or lowered.

7. 2. The image reading device according to claim 1, wherein the distance between the reflecting portion and the light reflective sensor is constant regardless of the lifting and lowering operation of the loading platform, and the width of the reflecting portion is narrower than the width of the detection range of the light reflective sensor.

8. a loading table for loading manuscripts; a lifting means for lifting and lowering the loading platform; a take-in means for taking in the topmost document stacked on the stacking table; a side plate disposed opposite a side surface of the loading platform; a reflecting portion provided on one of the side surface of the loading platform and the side plate; a light reflective sensor provided on a side surface of the loading platform and the other of the side plates on which the reflecting portion is not provided; a height calculation means for calculating the height of the loading platform, The distance between the reflecting portion and the light reflective sensor changes as the loading platform is raised or lowered, thereby changing the reflectivity of the reflecting portion in the height direction. The image reading device is characterized in that the height calculation means calculates the height of the loading platform based on a light reception output value from the light reflection sensor.

9. 9. The image reading device according to claim 8, wherein the reflecting portion comprises a short-distance portion, a long-distance portion, and a changing portion.

Images