Patent Description:
In <CIT>, a sheet supply device including: an arranging unit on which a sheet bundle having a plurality of sheets stacked in an up-down direction is arranged; a blowing unit that blows air toward the sheet bundle arranged on the arranging unit to float the sheet located at an upper layer of the sheet bundle; a sticking/transporting mechanism that is provided above the arranging unit, causes the sheet floated by the blowing unit to stick to the sticking/transporting mechanism, and transports the sheet in a predetermined transport direction; a photographing unit that photographs the sheet floated by the blowing unit; and a lighting unit that irradiates the sheet floated by the blowing unit with light a plurality of times during one exposure in the photographing unit. <CIT> discloses a sheet feeding device and image formation apparatus including: air spray means which floats a sheet on the upper part of a sheet bundle by spraying the air to the sheet bundle loaded on a sheet loading part; feeding means which feeds the floating uppermost sheet; imaging means which images the sheet floated by the air spray means; illumination means which illuminates the floating sheet; and change means which changes the light irradiation range of the illumination means in the vertical direction.

The following disclosure serves a better understanding of the present invention. An object of the present disclosure is to provide a medium supply device capable of accurately detecting a plurality of media photographed by a photographing unit, compared to a case where media are irradiated with only light from one identical position in an up-down direction, and an image forming apparatus.

According to the present invention, there is provided a medium supply device including: a loading unit on which media are loadable in an up-down direction; a supply unit that supplies air to a plurality of the media loaded on the loading unit to float and separate the plurality of media; a transporting unit that sequentially feed the media that are floated and separated by the supply unit; a photographing unit that photographs a state in which the media are floated and separated by the supply unit; and a light irradiation unit that irradiates end portions of the media on a photographing side of the photographing unit with light from a plurality of different positions in the up-down direction.

According to a second aspect of the present disclosure, the medium supply device according to the first aspect may further include: at least one processor, in which the processor may be configured to: in a case where it is determined by an image photographed by the photographing unit that there is a possibility of a jam or double feed of the media, change the amount of air supplied by the supply unit.

According to a third aspect of the present disclosure, the medium supply device according to the first or second aspect may further include: at least one processor, in which the processor may be configured to: for each photographed image photographed by the photographing unit, change a position in the up-down direction at which the media are irradiated with light by the light irradiation unit and acquire the photographed image.

According to the present invention, in the medium supply device according to any one of the first to third aspects, the light irradiation unit may have a plurality of lighting units arranged at different positions in the up-down direction.

According to a fifth aspect of the present disclosure, in the medium supply device according to the fourth aspect, the plurality of lighting units may be arranged so as to be displaced in a direction toward or away from the end portions of the media on the photographing side of the photographing unit.

According to a sixth aspect of the present disclosure, in the medium supply device according to the fourth or fifth aspect, the photographing unit may be arranged at a position facing the plurality of media floated and separated by the supply unit, and the lighting unit may be arranged at least on an upper side in the up-down direction with respect to the photographing unit.

According to a seventh aspect of the present disclosure, in the medium supply device according to the sixth aspect, the plurality of lighting units may be arranged on the upper side and a lower side in the up-down direction with respect to the photographing unit.

According to an eighth aspect of the present disclosure, in the medium supply device according to any one of the first to seventh aspects, the photographing unit may be arranged at a center portion in the up-down direction facing the plurality of media floated and separated by the supply unit.

According to a ninth aspect of the present disclosure, in the medium supply device according to the third aspect, the processor may be configured to: exclude an area inappropriate for discriminating the media from relative positions between the position in the up-down direction at which light is emitted by the light irradiation unit and the media, and detect the end portions of the media of the photographed image corresponding only to an area in which the media are discriminable.

According to a tenth aspect of the present disclosure, in the medium supply device according to the third or ninth aspect, the processor may be configured to: compare positions of the end portions of the media detected for each photographed image with each other, determine that, in a case where a difference between the positions of the end portions of the media is equal to or less than a threshold, the media are identical, and detect, in a case where the difference is larger than the threshold, a new medium.

According to an eleventh aspect of the present disclosure, in the medium supply device according to the tenth aspect, the processor may be configured to: create a filter thickened by a width in a thickness direction determined from a center position of the end portion of the medium detected in an nth photographed image, and when a center position of the end portion of the medium detected in an (n + <NUM>)th photographed image falls within the filter, determine that the media are identical, and update the filter to a new filter thickened by the width in the thickness direction determined from the center position of the end portion of the medium of the (n + <NUM>)th photographed image.

According to a twelfth aspect of the present disclosure, an image forming apparatus includes: the medium supply device according to any one of the first to eleventh aspects; and an image forming unit that forms an image on the medium supplied by the medium supply device.

According to the medium supply device according to the present invention, the plurality of media photographed by the photographing unit can be accurately detected compared to a case where media are irradiated with only light from one identical position in an up-down direction.

According to the medium supply device according to the second aspect, a jam or double feed of the media can be suppressed compared to a case where the amount of air supplied is always constant.

According to the medium supply device according to the third aspect, the plurality of media photographed by the photographing unit can be accurately detected compared to a case where a plurality of photographed images are acquired by irradiating media with light from the identical position in an up-down direction.

According to the medium supply device according to the present invention, a structure of the medium supply device is simple compared to a case where one light irradiation unit is used to irradiate media with light from different positions in an up-down direction.

According to the medium supply device according to the fifth aspect, the plurality of media photographed by the photographing unit can be accurately detected compared to a case where a plurality of irradiation units are arranged at the identical distance with respect to end portions of media on a photographing side of a photographing unit.

According to the medium supply device according to the sixth aspect, the plurality of media photographed by the photographing unit can be accurately detected, compared to a case where a lighting unit is arranged only on a lower side in an up-down direction with respect to a photographing unit.

According to the medium supply device according to the seventh aspect, the plurality of media photographed by the photographing unit can be accurately detected, compared to a case where a lighting unit is arranged only on an upper side in an up-down direction with respect to a photographing unit.

According to the medium supply device according to the eighth aspect, the plurality of media photographed by the photographing unit can be accurately detected, compared to a case where a photographing unit is arranged on a lower side in an up-down direction of a plurality of media floated and separated by a supply unit.

According to the medium supply device according to the ninth aspect, the plurality of media can be accurately detected, compared to a case where end portions of media are detected from the entire photographed image.

According to the medium supply device according to the tenth aspect, the plurality of media can be accurately detected, compared to a case where identity of detected media for each photographed image is not determined.

According to the medium supply device according to the eleventh aspect, the plurality of media can be accurately detected compared to a case where the identical filter is always used.

According to the image forming apparatus according to the twelfth aspect, the plurality of media photographed by the photographing unit can be accurately detected compared to a case where media are irradiated with light from one identical position in an up-down direction.

Hereinafter, exemplary embodiments for carrying out the present invention will be described. In the following description, a direction indicated by arrow X in the drawings is defined as an apparatus width direction, and a direction indicated by arrow Y is defined as an apparatus height direction. In addition, a direction (arrow Z direction) orthogonal to each of the apparatus width direction and the apparatus height direction is defined as an apparatus depth direction.

<FIG> shows a part of a medium supply device <NUM> according to a first exemplary embodiment, and <FIG> shows an example of an image forming apparatus <NUM> including the medium supply device <NUM>.

As shown in <FIG>, the image forming apparatus <NUM> includes an image forming unit <NUM> that forms an image on a sheet P as an example of a medium, and the medium supply device <NUM> that supplies sheets P to the image forming unit <NUM> one by one. Although not shown, a transporting unit that transports the sheet P to an image forming position of the image forming unit <NUM> is provided inside the image forming apparatus <NUM>. A configuration and an arrangement of the image forming unit <NUM> and the transporting unit are not particularly limited. The medium supply device <NUM> may also be configured to be attached to an image forming apparatus body as an option.

As shown in <FIG>, the medium supply device <NUM> includes a loading unit <NUM> on which sheets P can be loaded in an up-down direction and a supply unit <NUM> that supplies air to a plurality of the sheets P loaded on the loading unit <NUM> to float and separate the sheets P. In addition, the medium supply device <NUM> includes a feeding unit <NUM> that sequentially feeds the sheets P floated and separated by the supply unit <NUM>. The feeding unit <NUM> is an example of a transporting unit. In addition, the medium supply device <NUM> includes a camera <NUM> as an example of a photographing unit that photographs a state in which the sheets P are floated and separated by the supply unit <NUM>, and a light irradiation unit <NUM> that irradiates end portions of the sheets P on a photographing side of the camera <NUM> with light. Furthermore, the medium supply device <NUM> includes a control device <NUM> that controls an operation of each unit. The control device <NUM> is an example of a processor.

As shown in <FIG>, the loading unit <NUM> includes a plate-shaped body 12A on which the plurality of sheets P can be loaded. Although not shown, the medium supply device <NUM> includes an elevating device that raises and lowers the plate-shaped body 12A in the up-down direction. The elevating device raises the plate-shaped body 12A so that a position of an uppermost sheet P of the sheets P loaded on an upper side of the plate-shaped body 12A reaches a predetermined height.

As shown in <FIG>, the medium supply device <NUM> is provided with side guides <NUM> that restrict positions of side portions of the sheets P loaded on the loading unit <NUM> in a width direction (in this example, the arrow Z direction). The side guides <NUM> are arranged on an upper side of the loading unit <NUM> and are provided on both sides of the side portions of the sheets P in the width direction (arrow Z direction). As an example, the side guide <NUM> is slidably attached to the loading unit <NUM> in the apparatus depth direction (arrow Z direction). The side guide <NUM> can be slid in the apparatus depth direction (arrow Z direction) according to a size of the sheet P. A movement range of the side guide <NUM> is limited by a stopper (length of a guide slit) or the like (not shown) so as not to interfere with the feeding unit <NUM>.

As shown in <FIG> and <FIG>, the supply unit <NUM> includes an air outlet <NUM> through which air is blown toward an upper side of the loading unit <NUM> in a direction from the side portion of the sheet P in the width direction (arrow Z direction). The air outlet <NUM> is arranged at a position facing an upper portion of the plurality of sheets P loaded on the upper side of the plate-shaped body 12A. The supply unit <NUM> blows air from the air outlet <NUM> between the plurality of sheets P to float and separate the plurality of sheets P loaded on the plate-shaped body 12A of the loading unit <NUM>.

The supply unit <NUM> includes a duct <NUM> connected to the air outlet <NUM> and a fan <NUM> provided upstream of the duct <NUM> in an air flow direction (see <FIG>). In the supply unit <NUM>, air is supplied to the air outlet <NUM> through the duct <NUM> by rotation of the fan <NUM>, and air is blown out from the air outlet <NUM> to the upper side of the loading unit <NUM>.

Although not shown, the air outlets <NUM> are provided on both sides of the side portions of the sheets P in the width direction (arrow Z direction). As an example, the air outlets <NUM> are provided at the side guides <NUM> on both sides of the side portions of the sheets P in the width direction (arrow Z direction). The duct <NUM> is branched into two pieces on a side downstream of the fan <NUM> in the air flow direction, and the air outlet <NUM> is provided at each downstream end portion of the branched portion of the duct <NUM>.

As shown in <FIG>, the feeding unit <NUM> transports the sheets P loaded on the upper side of the plate-shaped body 12A of the loading unit <NUM> one by one in an arrow A direction, that is, toward a right side in the apparatus width direction (right side in an arrow X direction). The feeding unit <NUM> includes a feeding roll (supply roll) <NUM> that feeds the uppermost sheet P on the upper side of the loading unit <NUM> one by one and a sticking unit <NUM> arranged inward of the feeding roll <NUM> in the apparatus width direction (left side in the arrow X direction). The sticking unit <NUM> causes the uppermost sheet P to stick to the sticking unit. Furthermore, the feeding unit <NUM> includes a pair of transporting rolls <NUM> that transport the sheet P fed by the feeding roll <NUM>.

As an example, in the feeding unit <NUM>, in a case where the sheet P caused to stick to the sticking unit <NUM> comes into contact with the feeding roll <NUM>, the sheet P is fed from the feeding roll <NUM> in the arrow A direction, and is transported in the arrow A direction by the transporting rolls <NUM>.

The camera <NUM> photographs a floated and separated state of the end portions of the sheets P. As shown in <FIG>, and <FIG>, the camera <NUM> is provided on a side of the side portions of the sheets P in the width direction (arrow Z direction). The camera <NUM> is arranged at a position facing the end portions of the sheet P loaded on the plate-shaped body 12A in the width direction (arrow Z direction). Accordingly, the camera <NUM> photographs the state in which the sheets P are floated and separated from an outside of the end portions of the sheets P in the width direction. As an example, the cameras <NUM> are provided on both sides of the end portions of the sheets P in the width direction (arrow Z direction).

As an example, the camera <NUM> is arranged on an upper portion side of the side guide <NUM>, and is arranged near the end portions of the sheets P on a downstream side in a feeding direction (arrow A direction) in the side guide <NUM>.

The light irradiation unit <NUM> irradiates the end portions of the sheets P with light when the end portions of the sheets P are photographed by the camera <NUM>. As shown in <FIG>, the light irradiation unit <NUM> irradiates the end portions of the sheets P on the photographing side of the camera <NUM> with light from a plurality of different positions in the up-down direction. The light irradiation unit <NUM> has a plurality of lighting units <NUM> arranged at different positions in the up-down direction. In the first exemplary embodiment, the plurality of lighting units <NUM> are four, and includes a first lighting unit 24A, a second lighting unit 24B, a third lighting unit 24C, and a fourth lighting unit 24D arranged from an upper side to a lower side in the up-down direction.

The plurality of lighting units <NUM> are arranged so as to be displaced in a direction toward or away from the end portions of the sheets P on the photographing side of the camera <NUM>. In the first exemplary embodiment, the first lighting unit 24A at an uppermost portion and the fourth lighting unit 24D at a lowermost portion are arranged on a side approaching the end portions of the sheets P on the photographing side of the camera <NUM>. The second lighting unit 24B and the third lighting unit 24C as intermediate portions in the up-down direction are arranged so as to be displaced in a direction away from the end portions of the sheets P on the photographing side of the camera <NUM> compared to the first lighting unit 24A and the fourth lighting unit 24D. In a plan view of the medium supply device <NUM>, the second lighting unit 24B and the third lighting unit 24C are arranged so as to overlap each other on a side toward the end portions of the sheets P in the width direction, and the first lighting unit 24A and the fourth lighting unit 24D are arranged so as to overlap each other on a side away from the end portions of the sheets P in the width direction.

As shown in <FIG>, the camera <NUM> is arranged at a position facing the plurality of sheets P that are floated and separated by air from the supply unit <NUM>. As an example, the camera <NUM> is arranged at a center portion in the up-down direction facing the plurality of sheets P that are floated and separated by air from the supply unit <NUM>. Here, the center portion in the up-down direction facing the plurality of sheets P refers to a center of a range in which the plurality of sheets P are scattered when a predetermined amount of air is blown. The first lighting unit 24A and the second lighting unit 24B are arranged on an upper side in the up-down direction with respect to the camera <NUM>. The third lighting unit 24C and the fourth lighting unit 24D are arranged on a lower side in the up-down direction with respect to the camera <NUM>.

As shown in <FIG>, in the light irradiation unit <NUM>, the first lighting unit 24A, the second lighting unit 24B, the third lighting unit 24C, and the fourth lighting unit 24D are turned on in a predetermined order, so that the end portions of the sheets P on the photographing side of the camera <NUM> are irradiated with light from the plurality of different positions in the up-down direction. The first lighting unit 24A, the second lighting unit 24B, the third lighting unit 24C, and the fourth lighting unit 24D have the identical configuration, and are described as a lighting unit <NUM> in a case where it is not necessary to distinguish between the four.

<FIG> is a block diagram showing a hardware configuration of devices mounted in the medium supply device <NUM>. As shown in <FIG>, the medium supply device <NUM> includes the control device <NUM>, the camera <NUM>, the supply unit <NUM>, and the light irradiation unit <NUM> as described above. The light irradiation unit <NUM> includes the first lighting unit 24A, the second lighting unit 24B, the third lighting unit 24C, and the fourth lighting unit 24D.

The control device <NUM> has each configuration of a central processing unit (CPU) <NUM>, a read only memory (ROM) <NUM>, a random access memory (RAM) <NUM>, a storage <NUM>, and an input/output interface <NUM>. The configurations are connected via a bus <NUM> to communicate with each other.

The CPU <NUM> is a central processing unit and executes various programs and controls each unit. The CPU <NUM> is an example of the processor. That is, the CPU <NUM> reads a program from the ROM <NUM> or the storage <NUM> and executes the program using the RAM <NUM> as a work area. The CPU <NUM> controls each configuration and performs various arithmetic processes according to the programs recorded in the ROM <NUM> or the storage <NUM>. In the present exemplary embodiment, a detection process program is stored in the ROM <NUM> or the storage <NUM>.

The ROM <NUM> stores various programs and various data. The RAM <NUM> temporarily stores programs or data as a work area. The storage <NUM> is configured by a hard disk drive (HDD) or a solid state drive (SSD), and stores various programs including an operating system and various data. A program of a printer driver is stored in the storage <NUM>. The CPU <NUM> reads the program of the printer driver from the storage <NUM> and executes the program to function as the printer driver.

The input/output interface <NUM> is an interface for communicating with each device mounted in the medium supply device <NUM>. The control device <NUM> is connected to the camera <NUM>, the supply unit <NUM>, and the light irradiation unit <NUM> via the input/output interface <NUM>. The camera <NUM>, the supply unit <NUM>, and the light irradiation unit <NUM> may be directly connected to each other via the bus <NUM>.

<FIG> is a block diagram showing an example of a functional configuration of the control device <NUM>.

As shown in <FIG>, the control device <NUM> has a light irradiation control unit <NUM>, a photographed image acquisition unit <NUM>, a sheet calculation unit <NUM>, a sheet state determination unit <NUM>, and an air supply amount changing unit <NUM> as functional configurations. The functional configuration is realized by the CPU <NUM> reading the detection process program stored in the ROM <NUM> or the storage <NUM>, deploying the detection process program into the RAM <NUM>, and executing the detection process program.

The light irradiation control unit <NUM> controls turning on and off of the plurality of lighting units <NUM> in the light irradiation unit <NUM>. More specifically, the light irradiation control unit <NUM> changes a position in the up-down direction at which the sheets P are irradiated with light by controlling turning on and off of the first lighting unit 24A, the second lighting unit 24B, the third lighting unit 24C, and the fourth lighting unit 24D constituting the plurality of lighting units <NUM> (see <FIG>). In the first exemplary embodiment, the position in the up-down direction at which the sheets P are irradiated with light by the plurality of lighting units <NUM> is changed for each frame photographed by the camera <NUM>. One frame is an example of one photographed image. As an example, the light irradiation control unit <NUM> turns on any one lighting unit <NUM> (one of the first lighting unit 24A, the second lighting unit 24B, the third lighting unit 24C, and the fourth lighting unit 24D) among the plurality of lighting units <NUM> in a predetermined order and turns off the other lighting units <NUM> when one lighting unit <NUM> is turned on.

The photographed image acquisition unit <NUM> acquires a photographed image of the end portions of the sheets P in the width direction (arrow Z direction) photographed by the camera <NUM>. The photographed image acquisition unit <NUM> acquires a plurality of photographed images in which the position in the up-down direction at which the sheets P are irradiated with light by the plurality of lighting units <NUM> is changed for each frame photographed by the camera <NUM>. As an example, in the medium supply device <NUM>, every time any one of the first lighting unit 24A, the second lighting unit 24B, the third lighting unit 24C, and the fourth lighting unit 24D is turned on in a predetermined order, the camera <NUM> photographs the end portions of the sheets P, so that the photographed image acquisition unit <NUM> acquires at least four photographed images.

The sheet calculation unit <NUM> calculates the position of the end portion of the sheet P in the width direction based on a photographed image of the end portion of the sheet P photographed by the camera <NUM> in the width direction (arrow Z direction). The sheet calculation unit <NUM> excludes a non-discriminable area <NUM> (see <FIG>) inappropriate for discriminating the sheets P from relative positions between the position in the up-down direction at which light is emitted by the light irradiation unit <NUM> and the sheets P and detects the end portions of the sheets P of the photographed image corresponding only to the discriminable area <NUM> (see <FIG> or the like) in which the sheets P are discriminable. The non-discriminable area <NUM> is an example of an area inappropriate for discriminating the sheets P, and the discriminable area <NUM> is an example of an area in which the sheets P are discriminable. The sheet calculation unit <NUM> calculates the positions of the end portions of the sheets P in the width direction in the discriminable area <NUM> to detect a floated and separated state of the end portions of the sheets P in the width direction. A method of detecting the floated and separated state of the end portions of the sheets P in the width direction will be described later.

The sheet state determination unit <NUM> determines whether or not there is a possibility of a jam or double feed of the sheets P from the floated and separated state of the end portions of the sheets P in the width direction. A condition for determining whether or not there is a possibility of a jam or double feed of the sheets P is stored in advance in the storage <NUM>. This condition will be described later.

The air supply amount changing unit <NUM> changes the amount of air supplied by the supply unit <NUM>. For example, the air supply amount changing unit <NUM> changes the amount of air supplied by the supply unit <NUM> in a case where it is determined that there is a possibility of a jam or double feed of the sheets P.

For example, in a case where the floated and separated state of the sheets P is insufficient (the number of sheets P floated and separated is small), the air supply amount changing unit <NUM> increases the amount of air supplied by the supply unit <NUM>. In addition, for example, in a case where the number of sheets P floated is too large and a plurality of sheets P are in a bundle and are not sufficiently separated, the air supply amount changing unit <NUM> reduces the amount of air supplied by the supply unit <NUM>. For example, changing the amount of air supplied by the supply unit <NUM> is executed by changing a rotation speed of the fan <NUM>.

Here, a configuration and problems of a medium supply device of a comparative example will be described.

Although not shown, the medium supply device of the comparative example includes one lighting unit of which a position in an up-down direction is fixed, and a camera. Then, an end portion of a sheet P in a width direction is photographed by the camera in a state of being irradiated with light by the one lighting unit.

In general, in a configuration in which a plurality of sheets P are floated and separated by air blown from a supply unit, the sheets P can easily move in units of several mm in a depth direction facing the camera. Therefore, in the medium supply device of the comparative example, when end portions of the plurality of sheets P are photographed by the camera in a state of being irradiated with light by the one lighting unit, there may be cases where brightness of the end portions of the plurality of sheets P in the up-down direction changes.

<FIG> is a photographed image obtained by photographing the end portions of the sheets P in the width direction with the camera in the medium supply device of the comparative example. As shown in <FIG>, in a first area <NUM> in the photographed image, the sheet P moved toward a back side in the depth direction with respect to the camera is darker than the other sheets P. This is because the sheet P moved toward the back side in the depth direction with respect to the camera is hidden by another sheet P directly above or directly below the sheet P, and is less likely to be hit by the light of the lighting unit, so that the sheet P looks darker than the other sheets P. Therefore, when a floated and separated state of the plurality of sheets P is detected, there may be cases where the sheets P in the first area <NUM> cannot be detected.

In addition, as shown in <FIG>, in a second area <NUM> in the photographed image, since the lighting unit irradiates the sheets P with light from a front side of the sheets P, upper surfaces of the sheets P shine. Therefore, there may be cases where the sheets P are erroneously detected as thick sheets P. In addition, depending on a position of the camera, as the sheets P are irradiated with light from the front side, lower surfaces of the sheets may shine, and there may be cases where the sheets P are also erroneously detected as thick sheets P.

On the other hand, in the medium supply device <NUM> of the first exemplary embodiment, in order to suppress erroneous detection of the sheets P, the following process of detecting the end portions of the sheets P is performed.

In the medium supply device <NUM>, a plurality of photographed images are acquired by photographing the end portions of the sheets P by the camera <NUM> in a state in which the position in the up-down direction at which the sheets P are irradiated with light by the plurality of lighting units <NUM> is changed. Furthermore, the CPU <NUM> of the control device <NUM> performs a process of detecting (for example, performing an image analysis) positions of the end portions of the sheets P in the width direction (arrow Z direction) based on the plurality of photographed images.

<FIG> schematically show states of the plurality of sheets P photographed by the camera <NUM> when turning-on positions of the plurality of lighting units <NUM> in the up-down direction are changed. In addition, in <FIG>, in order to facilitate understanding of which sheet P is among the plurality of sheets P, a position of the sheet P from the top is indicated by a number in parentheses.

As shown in <FIG>, when the fourth lighting unit 24D at the lowermost portion in the up-down direction is turned on, the second, fourth, fifth, sixth, and eighth sheets P from the top are recognized as the end portions of the sheets P. The first, third, and seventh sheets P are displaced toward the back side in the depth direction with respect to the camera <NUM>, and are less likely to be detected. In addition, there may be cases where upper surfaces or lower surfaces of the ninth and tenth sheets P appear shining, resulting in erroneous detection. Therefore, when the fourth lighting unit 24D at the lowermost portion in the up-down direction is turned on, the CPU <NUM> sets the first to eighth sheets P as the discriminable area <NUM>, and sets the ninth and tenth sheets P as the non-discriminable area <NUM>.

As shown in <FIG>, when the third lighting unit 24C that is second from the lower side in the up-down direction is turned on, the first, second, fourth, fifth, sixth, and seventh sheets P from the top are recognized as the end portions of the sheets P. The third sheet P is displaced toward the back side in the depth direction with respect to the camera <NUM>, and is less likely to be detected. In addition, there may be cases where upper surfaces or lower surfaces of the eighth, ninth, and tenth sheets P appear shiny, resulting in erroneous detection. Therefore, when the third lighting unit 24C that is second from the lower side in the up-down direction is turned on, the CPU <NUM> sets the first to seventh sheets P as the discriminable area <NUM>, and sets the eighth to tenth sheets P as the non-discriminable area <NUM>.

As shown in <FIG>, when the second lighting unit 24B that is second from the upper side in the up-down direction is turned on, the third, fourth, fifth, sixth, eighth, ninth, and tenth sheets P from the top are recognized as the end portions of the sheets P. The seventh sheet P is displaced toward the back side in the depth direction with respect to the camera <NUM>, and is less likely to be detected. In addition, there may be cases where upper surfaces or lower surfaces of the first and second sheets P appears shining, resulting in erroneous detection. Therefore, when the second lighting unit 24B that is second from the upper side in the up-down direction is turned on, the CPU <NUM> sets the third to tenth sheets P as the discriminable area <NUM>, and sets the first to second sheets P as the non-discriminable area <NUM>.

As shown in <FIG>, when the first lighting unit 24A at the uppermost portion in the up-down direction is turned on, the first, second, fourth, fifth, sixth, and eighth sheets P from the top are recognized as the end portions of the sheets P. The third and seventh sheets P are displaced toward the back side in the depth direction with respect to the camera <NUM>, and are less likely to be detected. In addition, the ninth and tenth sheets P are hidden by the eighth sheet P, and are less likely to be detected. When the plurality of sheets P are floated and separated, since the first lighting unit 24A is arranged on the upper side in the up-down direction with respect to the first sheet P from the top, the sheets P are not irradiated with light from the front surface side, and shining of the upper surfaces or lower surfaces of the sheets P is suppressed. Therefore, when the first lighting unit 24A at the uppermost portion in the up-down direction is turned on, the CPU <NUM> sets the first to tenth sheets P as the discriminable area <NUM>. As shown in <FIG>, the discriminable area <NUM> and the non-discriminable area <NUM> are determined based on the relative positions between the position in the up-down direction at which light is emitted by the plurality of lighting units <NUM> of the light irradiation unit <NUM> and the sheets P.

A part (A) in <FIG> shows an example of actual positions of a plurality of sheets P. A part (B) in <FIG> shows an example of an image of a first frame when the plurality of sheets P are photographed by the camera <NUM>, and a part (C) in <FIG> shows an example of an image of a second frame when the plurality of sheets P are photographed by the camera <NUM>. As shown in the part (A) in <FIG>, first to fifth sheets P are arranged at equal intervals. As shown in the part (B) in <FIG>, a third sheet P is not visible in the image of the first frame. Therefore, in the image of the first frame, the third sheet P is excluded. As shown in the part (C) in <FIG>, a fourth sheet P is not visible in the image of the second frame. Therefore, in the image of the second frame, the fourth sheet P is excluded.

Parts (A) and (B) in <FIG> show an example of a flow of the detection process of the end portions of the sheets P by the CPU <NUM> in the case shown in <FIG>. As shown in the part (A) in <FIG>, the CPU <NUM> excludes the third sheet P in the image of the first frame, and detects center positions (that is, center coordinate positions in a thickness direction of the sheets P) of the first, second, fourth, and fifth sheets P. Furthermore, for the first, second, fourth, and fifth sheets P, the CPU <NUM> creates filters <NUM> thickened by a width in the thickness direction determined from the center positions of the end portions of the sheets P.

As shown in the part (B) in <FIG>, the CPU <NUM> excludes the fourth sheet P in the image of the second frame, and detects center positions (that is, center coordinate positions in a thickness direction of the sheets P) of the first, second, third, and fifth sheets P. When the center positions of the first, second, third, and fifth sheets P fall within the filters <NUM> created based on the image of the first frame, the CPU <NUM> determines the identical sheets P (see the figure shown on the left side of the part (B) in <FIG>).

The CPU <NUM> performs an AND operation on the filters <NUM> shown on the right side of the part (A) in <FIG> and the center positions of the sheets P shown on the left side of the part (B) in <FIG>, and calculates a center position of a new sheet P. More specifically, as shown in the part (B) in <FIG>, in the image of the second frame, for the first, second, third, and fifth sheets P, the CPU <NUM> creates the filters <NUM> thickened by the width in the thickness direction determined from the center positions of the end portions of the sheets P. Furthermore, in the image of the second frame, the CPU <NUM> creates a filter <NUM> at the identical position as the filter <NUM> of the fourth sheet P (see the part (A) in <FIG>) created based on the image of the first frame. That is, in the image of the second frame, the filter <NUM> is updated. The CPU <NUM> repeats the above process in the order of frames photographed by the camera <NUM>.

The above detection process is summarized as follows. The CPU <NUM> detects center positions of sheets P of an image in an nth frame (that is, center coordinate positions of sheets P in a thickness direction) (see the part (A) in <FIG>). A case where an end portion of a sheet P is unclear, or a sheet P in the non-discriminable area <NUM> (that is, the sheet P having a possibility that a lower surface or an upper surface of the sheet P shines) is ignored. The image in the nth frame is an example of an nth photographed image. The CPU <NUM> creates filters <NUM> thickened by the width in the thickness direction determined from the center positions of the end portions of the sheets P detected in the image of the nth frame (see the part (A) in <FIG>).

Similarly to the above description, the CPU <NUM> detects the center positions of the sheets P (that is, the center coordinate positions of the sheets P in the thickness direction) of an image of an (n + <NUM>)th frame (see the part (B) in <FIG>). The image in the (n + <NUM>)th frame is an example of an (n + <NUM>)th photographed image. The CPU <NUM> compares the positions of the end portions of the sheets P detected for each image of each frame by the camera <NUM> with each other, determines that, in a case where a difference between the positions of the end portions of the sheets P is equal to or less than a threshold, the sheets P are identical, and detects, in a case where the difference is larger than the threshold, a new sheet P. In the first exemplary embodiment, the CPU <NUM> determines that the sheets P are identical when the center position of the end portion of the sheet P detected in the (n + <NUM>)th frame falls within the filter <NUM>. The CPU <NUM> is updated with a new filter <NUM> that is thickened by the width in the thickness direction determined from the center position of the end portion of the sheet P of the image of the (n + <NUM>)th frame (see the part (B) in <FIG>). When the sheet P is excluded in the image of the (n + <NUM>)th frame, the CPU <NUM> creates the filter <NUM> at the identical position as the filter <NUM> in the sheet P in the image of the nth frame. By repeating the above process, the CPU <NUM> detects the positions of the end portions of the sheets P, that is, performs an image analysis of the end portions of the sheets P.

Next, a condition for determining whether or not there is a possibility of a jam or double feed of the sheets P by the control device <NUM> will be described.

The CPU <NUM> of the control device <NUM> detects the floated and separated state of the end portions of the sheets P by detecting the positions of the end portions of the sheets P by the detection process described above. Furthermore, the CPU <NUM> determines whether or not there is a possibility of a jam or double feed of the sheets P. The condition for determining that there is a possibility of a jam or double feed of the sheets P is a case where sheets P of which the number is a first threshold (for example, four), which is a predetermined number, or less are floated. In addition, the condition for determining that there is a possibility of a jam or double feed of the sheets P is a case where sheets P of which the number is a second threshold (for example, three), which is a predetermined number, or more are not separated but are in a bundle. In the above case, the CPU <NUM> determines that there is a possibility of a jam or double feed of the sheets P. The first threshold and the second threshold described above can be changed.

Parts (A) to (C) in <FIG> show examples of a state of the sheets P when air is blown from the air outlet <NUM> of the supply unit <NUM> toward the sheets P loaded on the plate-shaped body 12A of the loading unit <NUM>. In a first example shown in the part (A) in <FIG>, about <NUM> sheets P on an upper portion side are independently separated and floated, so that the floated and separated state of the sheets P is good. In this state, even in a case where the sheets P are sequentially transported by the feeding unit <NUM>, a double feed of the sheets P or the like is less likely to occur. In such a case, based on the above condition, the CPU <NUM> determines that there is no possibility of a jam or double feed of the sheets P.

In a second example shown in the part (B) in <FIG>, the number of sheets P floated is only about one, and the floated and separated state of the sheets P is insufficient. In this state, in a case where the sheets P are sequentially transported by the feeding unit <NUM>, there is a possibility of a supply failure (that is, misfeed) in which the sheets P are not smoothly supplied. In such a case, based on the above condition, the CPU <NUM> determines that there is a possibility of a jam or double feed of the sheets P.

In a third example shown in the part (C) in <FIG>, since air is blown too strongly from the air outlet <NUM>, the sheets P on the upper portion side are in a bundle and are floated, so that the floated and separated state of the sheets P is insufficient. In this state, in a case where the sheets P are sequentially transported by the feeding unit <NUM>, there is a possibility of a double feed of the sheets P. In such a case, based on the above condition, the CPU <NUM> determines that there is a possibility of a jam or double feed of the sheets P.

Next, actions of the first exemplary embodiment will be described.

<FIG> is a flowchart showing a flow of the detection process in charge of the control device <NUM>. The detection process is performed by the CPU <NUM> reading the detection process program from the ROM <NUM> or the storage <NUM>, deploying the detection process program into the RAM <NUM>, and executing the detection process program.

Before the detection process shown in <FIG> is executed, a user instructs the image forming apparatus <NUM> to print image data on the sheets P. In a case where the image forming apparatus <NUM> receives the printing instruction, the medium supply device <NUM> supplies air through the supply unit <NUM> to float and separate the sheets P loaded on the loading unit <NUM>.

The CPU <NUM> starts supplying the sheets P (step S201).

The CPU <NUM> acquires a plurality of photographed images in which the end portions of the sheets P in the width direction are photographed by the camera <NUM> (step S202). As shown in <FIG>, in the medium supply device <NUM>, the end portions of the sheets P are photographed by the camera <NUM> in a state in which the position in the up-down direction at which the sheets P are irradiated with light by the plurality of lighting units <NUM> constituting the light irradiation unit <NUM> is changed. Accordingly, the CPU <NUM> acquires the plurality of photographed images in which the end portions of the sheets P in the width direction are photographed by the camera <NUM>.

The CPU <NUM> detects a state of the sheets P, that is, a floated and separated state of the end portions of the sheets P (step S203). As shown in <FIG>, the CPU <NUM> excludes the non-discriminable area <NUM> in the plurality of photographed images, and detects the end portions of the sheets P of the photographed image corresponding only to the discriminable area <NUM>. As shown in <FIG> and <FIG>, the CPU <NUM> performs the detection process of the end portions of the sheets P in the order of the photographed images photographed by the camera <NUM>, based on the flow of the detection process of the end portions the sheets P. The CPU <NUM> detects the positions of the end portions of the sheets P by repeating the process shown in <FIG> (that is, performs an image analysis of the positions of the end portions of the sheets P). Accordingly, the CPU <NUM> detects the floated and separated state of the end portions of the sheets P.

The CPU <NUM> determines whether or not there is a possibility of a jam or double feed of the sheets P (step S204). For example, the CPU <NUM> determines whether or not there is a possibility of a jam or double feed of the sheets P based on the condition of the detection.

In a case where there is no possibility of a jam or double feed of the sheets P (NO in step S204), the CPU <NUM> continues an operation of supplying the sheets P (step S205). That is, the amount of air supplied by the supply unit <NUM> is not changed.

In a case where there is a possibility of a jam or double feed of the sheets P (YES in step S204), the CPU <NUM> changes the amount of air supplied by the supply unit <NUM> (step S206). Accordingly, the floated and separated state of the sheets P loaded on the loading unit <NUM> are adjusted. Furthermore, the CPU <NUM> returns to the process of step S202. Accordingly, the process based on the detection process program in charge of the control device <NUM> is ended.

In addition, after step S206, in a case where a predetermined time has elapsed, the CPU <NUM> may display an alert indicating that there is a possibility of a jam or double feed of the sheets P, and stop supplying of the sheets P.

In the medium supply device <NUM> described above, the light irradiation unit <NUM> irradiates the end portions of the sheets P on the photographing side of the camera <NUM> with light from a plurality of different positions in the up-down direction, the camera <NUM> photographs the floated and separated state of the sheets P. Therefore, in the medium supply device <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected compared to a case where sheets are irradiated with only light from one identical position in an up-down direction. Accordingly, a transport failure of the sheets P is reduced compared to the case where sheets are irradiated with only light from one identical position in an up-down direction.

In addition, in the medium supply device <NUM>, the CPU <NUM> changes the amount of air supplied by the supply unit <NUM> in a case where it is determined by the image photographed by the camera <NUM> that there is a possibility of a jam or double feed of the sheets P. Therefore, in the medium supply device <NUM>, a jam or double feed of the sheets P can be suppressed compared to a case where the amount of air supplied is always constant.

In addition, in the medium supply device <NUM>, for each photographed image photographed by the camera <NUM>, the CPU <NUM> changes the position in the up-down direction at which the sheets P are irradiated with light by the light irradiation unit <NUM> and acquires the photographed images. Therefore, in the medium supply device <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected compared to a case where a plurality of photographed images are acquired by irradiating sheets with light from the identical position in an up-down direction.

In addition, in the medium supply device <NUM>, the light irradiation unit <NUM> has the plurality of lighting units <NUM> arranged at different positions in the up-down direction. Therefore, a structure of the medium supply device <NUM> is simple compared to a case where one light irradiation unit is used to irradiate sheets with light from different positions in an up-down direction.

In addition, in the medium supply device <NUM>, the plurality of lighting units <NUM> are arranged so as to be displaced in a direction toward or away from the end portions of the sheets P on the photographing side of the camera <NUM>. Therefore, in the medium supply device <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected compared to a case where a plurality of irradiation units are arranged at the identical distance with respect to end portions of sheets on a photographing side of a camera.

In addition, in the medium supply device <NUM>, the camera <NUM> is arranged at a position facing the plurality of sheets P that are floated and separated by the supply unit <NUM>, and the lighting unit <NUM> is arranged at least on the upper side in the up-down direction with respect to the camera <NUM>. That is, the lighting unit <NUM> is arranged at a position close to the uppermost sheet P fed by the feeding unit <NUM>. Therefore, in the medium supply device <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected, compared to a case where a lighting unit is arranged only on a lower side in an up-down direction with respect to a camera.

In addition, in the medium supply device <NUM>, the plurality of lighting units <NUM> are arranged on the upper side and the lower side in the up-down direction with respect to the camera <NUM>. Therefore, in the medium supply device <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected, compared to a case where a lighting unit is arranged only on an upper side in an up-down direction with respect to a camera.

In addition, in the medium supply device <NUM>, the camera <NUM> is arranged at a center portion in the up-down direction facing the plurality of sheets P that are floated and separated by the supply unit <NUM>. Therefore, in the medium supply device <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected, compared to a case where a camera is arranged on a lower side in an up-down direction of a plurality of media floated and separated by a supply unit.

In addition, in the medium supply device <NUM>, the CPU <NUM> excludes the non-discriminable area <NUM> inappropriate for discriminating the sheets P from the relative positions between the position in the up-down direction at which light is emitted by the light irradiation unit <NUM> and the sheets P, and detects the end portions of the sheets P of the photographed image corresponding only to the discriminable area <NUM> in which the sheets P are discriminable. Therefore, in the medium supply device <NUM>, the plurality of sheets P can be accurately detected, compared to a case where end portions of sheets are detected from the entire photographed image.

In addition, in the medium supply device <NUM>, the CPU <NUM> compares the positions of the end portions of the sheets P detected for each photographed image with each other, determines that, in a case where a difference between the positions of the end portions of the sheets P is equal to or less than the threshold, the sheets P are identical, and detects, in a case where the difference is larger than the threshold, a new sheet P. Therefore, in the medium supply device <NUM>, the plurality of sheets P can be accurately detected, compared to a case where identity of detected sheets for each photographed image is not determined.

In addition, in the medium supply device <NUM>, the CPU <NUM> creates the filter <NUM> thickened by the width in the thickness direction determined from the center position of the end portion of the sheet P detected in the nth photographed image. Then, the CPU <NUM> determines that the sheets P are identical when the center position of the end portion of the sheet P detected in the (n + <NUM>)th photographed image falls within the filter <NUM>, and updates the filter <NUM> to a new filter <NUM> thickened by the width in the thickness direction determined from the center position of the end portion of the sheet P of the (n + <NUM>)th photographed image. Therefore, in the medium supply device <NUM>, the plurality of sheets P can be accurately detected compared to a case where an identical filter is always used.

In addition, the image forming apparatus <NUM> includes the medium supply device <NUM> and the image forming unit <NUM> that forms an image on the sheet P supplied by the medium supply device <NUM>. Therefore, in the image forming apparatus <NUM>, the plurality of sheets P photographed by the camera <NUM> can be accurately detected compared to a case where sheets are irradiated with light from one identical position in an up-down direction.

In the medium supply device of the first exemplary embodiment, the number of the plurality of lighting units <NUM> can be changed. For example, it is preferable that the plurality of lighting units <NUM> are arranged on at least the upper side in the up-down direction with respect to the camera <NUM>. In addition, the position of the plurality of lighting units <NUM> in the depth direction with respect to the end portions of the sheets P on the photographing side of the camera <NUM> may be changed.

In addition, in the medium supply device of the first exemplary embodiment, a positional relationship between the plurality of lighting units <NUM> and the camera <NUM> in the up-down direction may be changed.

In addition, in the medium supply device of the first exemplary embodiment, the light irradiation unit <NUM> can be changed to another configuration as long as the end portions of the sheets P on the photographing side of the camera <NUM> are irradiated with light from a plurality of different positions in the up-down direction. For example, the light irradiation unit may have one lighting unit, and the lighting unit may be configured to move in the up-down direction. Alternatively, one light irradiation unit may be provided and configured to change a shining position in the up-down direction using a mirror that reflects light.

In addition, in the medium supply device of the first exemplary embodiment, ranges of the discriminable area <NUM> and the non-discriminable area <NUM> can be changed according to the relative positions between the turning-on positions of the lighting units <NUM> and the sheets P.

In addition, in the medium supply device of the first exemplary embodiment, the camera <NUM> is provided on each of both sides of the sheets P in the width direction, but the present disclosure is not limited to this configuration. For example, the camera <NUM> may be configured to be provided on either one side of the sheets P in the width direction.

The process of the medium supply device <NUM> described above can also be realized by a dedicated hardware circuit. In this case, the process may be executed by one hardware or may be executed by a plurality of pieces of hardware.

In addition, the program for operating the medium supply device <NUM> may be provided by a computer-readable recording medium such as a Universal Serial Bus (USB) memory, a flexible disk, or a Compact Disc Read Only Memory (CD-ROM), or may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to a memory, a storage, or the like and stored. In addition, for example, this program may be provided as a single application software, or may be incorporated into software of each device as a function of the medium supply device <NUM> and the image forming apparatus <NUM>.

Although the present invention has been described in detail with respect to a specific exemplary embodiment, the present invention is not limited to such an exemplary embodiment, and it will be apparent to a person skilled in the art that various other exemplary embodiments are possible within the scope of the appended claims.

Claim 1:
A medium supply device (<NUM>) comprising:
a loading unit (<NUM>) on which media (P) are loadable in an up-down direction;
a supply unit (<NUM>) that supplies air to a plurality of the media (P) loaded on the loading unit (<NUM>) to float and separate the plurality of media (P);
a transporting unit (<NUM>) that sequentially feed the media (P) that are floated and separated by the supply unit (<NUM>);
a photographing unit (<NUM>) that photographs a state in which the media (P) are floated and separated by the supply unit (<NUM>); and
a light irradiation unit (<NUM>) that irradiates end portions of the media (P) on a photographing side of the photographing unit (<NUM>) with light from a plurality of different positions in the up-down direction,
the medium supply device (<NUM>) being characterized in that:
the light irradiation unit (<NUM>) has a plurality of lighting units (<NUM>, 24A, 24B, 24C, 24D) arranged at different positions in the up-down direction.