JP2010052372A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which has a simple constitution, and in which a cleaning performance for a moving-rotating blade does not deteriorate even when the position of the moving-rotating blade is shifted. <P>SOLUTION: This image forming apparatus includes: a sub scanning conveying section 30 which conveys a paper sheet P; an image forming section 40 which forms an image with ink on the paper sheet P conveyed by the sub scanning carrying section 30; and a cutting section 100 which cuts the paper sheet P after the image formation in the width direction orthogonal to a transfer material conveying direction. In the image forming apparatus, the cutting section 100 includes: a shuttle member 140 which reciprocates in the width direction; the movable rotating blade 150 which cuts the paper sheet P while being supported by the shuttle member 140; and a cleaning member 160 which removes the ink adherent to the movable rotating blade by following the movement of the movable rotating blade 150 while being rockably supported by the shuttle member 140. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a printing apparatus having a transfer material cutting function, and in particular, it is possible to maintain the cutting performance of the cutting means by cleaning the cutting means whose cutting ability has deteriorated due to adhesion of toner, ink or the like. The present invention relates to an image forming apparatus.

An electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile machine, and an ink jet printer have a configuration in which an image forming unit (printing unit) forms an image on a transfer material fed from a paper feeding unit. I have. An image forming apparatus having a cutting function for cutting an unnecessary portion of the transfer material is also known.
For example, in Patent Document 1, a notch having a required width is formed along the outer edge of the paper, and after forming an image with the inner cut surface and the outer cut surface being in close contact with each other, the outer side of the paper is removed. An image forming apparatus for obtaining a printed material without a border on an inner sheet is described. However, when the paper is cut before image formation as in Patent Document 1, it is necessary to ensure the page interval, and there is a limit to improving the productivity.
Therefore, in order to increase the image forming speed and shorten the total image forming time, it is desirable to have a configuration in which the sheet is cut immediately after image formation. Immediately after image formation, unfixed toner and undried ink are attached to the paper.If the paper is cut, the toner or ink may adhere to the cutter, which may contaminate the paper or deteriorate the cutting performance. The problem is how to clean the cutter.
For example, in patent document 2, the cleaner holding member provided with the cleaner is moved in the axial direction of the rotary blade, the tip of the blade is wiped off by the cleaner at the tip, and the rotary blade is cleaned.
Moreover, in patent document 3, the foaming polyurethane product which can contact | abut to a rotary blade and can remove the adhesion component adhering to this in the vicinity of the both ends of the moving range of the rotary blade (roller cutter) which cut | disconnects a photosensitive pressure sensitive recording medium The cleaning member is arranged.
JP 2008-36991 A JP-A-7-148689 JP-A-11-231425

However, in the invention described in Patent Document 2, a mechanism for moving the cleaning member must be provided, and the apparatus configuration is complicated.
Further, the invention described in Patent Document 3 has a problem that the cleaning performance deteriorates when the rotary blade moves for some reason and the positional relationship between the cleaning member and the movable rotary blade is deviated.
The present invention has been made in view of the above-described problems, and provides an image forming apparatus that has a simple configuration and that does not deteriorate the cleaning performance even when the position of the moving rotary blade is deviated. Objective.

In order to solve the above-described problems, the invention according to claim 1 includes a conveying unit that conveys a transfer material, an image forming unit that forms an image on a transfer material conveyed by the conveying unit with a recording agent, and A cutting unit configured to cut a transfer material image-formed by the image forming unit in a width direction perpendicular to the transfer material conveyance direction, and the cutting unit includes a shuttle member that reciprocates in the width direction; A moving rotary blade that is supported by the shuttle member and cuts the transfer material, and a recording agent that is swingably supported by the shuttle member and follows the movement of the moving rotary blade to remove the recording agent attached to the moving rotary blade. And an image forming apparatus including a cleaning member.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect of the present invention, the image forming apparatus further includes a discharge recording agent tank that collects the recording agent removed by the cleaning member, and the bottom surface of the cleaning member is disposed on the discharge recording. The image forming apparatus is inclined toward the agent tank.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, a pinion gear member inserted and fixed to a rotation shaft that rotates the movable rotary blade, and a movable range of the shuttle member. An image forming apparatus including a rack gear member meshing with the pinion gear member.
According to a fourth aspect of the present invention, there is provided the image forming apparatus according to any one of the first to third aspects, wherein the cleaning member, the movable rotary blade, and the fixed blade have a water repellent function. Features a forming device.

  According to the present invention, since the cleaning member for cleaning the moving rotary blade follows the position fluctuation of the moving rotary blade, the positional relationship between the moving rotary blade and the cleaning member is always kept constant, and the cleaning performance is improved. It can be stabilized.

Embodiments of the present invention will be described below with reference to the accompanying drawings. An outline of an example of an image forming apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing the overall configuration of the image forming apparatus.
The image forming apparatus includes an image reading unit 10 that reads an image of a document inside the apparatus main body 1 and a sheet feeding unit that stacks sheets P (transfer material) and feeds the sheets one by one toward the image forming unit 40. 20, an image forming unit 40 for forming an image on the sheet P, and an image-formed sheet P in a desired size. A cutting unit 100 for cutting, a paper discharge transport unit 50 for transporting the paper P after cutting, and a paper discharge tray 60 for placing the paper P that is discharged outside the apparatus after image formation is provided.
The image reading unit 10 is an input unit for image data formed by the image forming unit 40. The image reading unit 10 includes a contact glass 11 on which a document is placed, a scanning optical system 14 including an illumination light source 12 and a mirror 13, a scanning optical system 17 including a mirror 15 and a mirror 16, and a scanning optical system 14. A lens 18 on which a document image read by moving the scanning optical system 17 enters, and an image reading element 19 that reads the document image incident on the lens 18 as an analog image signal are provided. The read analog image signal is converted into a digital image, subjected to image processing, and becomes print data. The print data is sent to the image forming unit 40 and printed on the paper P.

The paper feeding unit 20 can be inserted into and removed from the apparatus main body 1, and separates the paper P in the paper feeding cassette 21 one by one from the paper feeding cassette 21, which is a storage means for stacking and storing a large number of paper P. A sheet feeding roller 22 and a friction pad 23 for feeding out, and a registration roller pair 24 for registering the sheet P to be fed are provided.
In addition, the paper feeding unit 20 includes a manual feed tray 25 for stacking and storing a large number of sheets P, a manual feed roller 26 for feeding the sheets P one by one from the manual feed tray 25, and the apparatus main body 1. On the lower side, an optional paper feed cassette and a vertical transport roller 27 for transporting paper P fed from the duplex unit are provided. The members for feeding the paper P to the sub-scanning conveyance unit 30 such as the sheet feeding roller 22, the registration roller pair 24, the manual feeding roller 26, the vertical conveyance roller 27, and the like are supplied by an HB type stepping motor via an electromagnetic clutch (not shown). The paper motor 28 is rotationally driven.

The sub-scanning conveyance unit 30 is a conveyance unit that sends the paper P in the conveyance direction during image formation.
The sub-scanning conveyance unit 30 includes an endless conveyance belt 31 that conveys the paper P fed from below facing the image forming unit 40, a conveyance roller 32 that is a driving roller that bridges the conveyance belt 31, and a tension. A driven roller 33 that is a roller, a charging roller 34 that charges the surface of the conveyance belt 31, a guide member 35 (not shown) that guides the conveyance belt 31 in a region facing the image forming unit 40, and a conveyance roller for the paper P The pressure roller 36 and the pressure roller 37 that are pressed against the conveying belt 31 at a position facing the conveying belt 31, the guide plate 38 that presses the upper surface side of the sheet P after image formation, and the sheet P after image formation are separated from the conveying belt 31. And a separation claw 39 for the purpose.
The transport belt 31 is configured to circulate in the paper transport direction as the transport roller 32 rotates. Further, an alternating high voltage is applied to the charging roller 34 from a high voltage power supply (not shown).
The image forming unit 40 is a unit that forms an image on the paper P by a so-called ink jet system that discharges ink (recording agent) droplets.
The image forming unit 40 can move the carriage 43 in the main scanning direction (width direction orthogonal to the sheet conveying direction) by a carriage guide 41 as a main guide member and a guide stay 42 (not shown) as a sub guide member. Hold on. On the carriage 43, a recording head 44 for each color that discharges black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink, and a recording head 44 for each color are required. And a sub-tank 45 for supplying inks of different colors. Each color ink is supplied from the ink cartridge 46 to the sub tank 45 via a tube (not shown).

In the image forming unit 40 in the present embodiment, the carriage 43 is reciprocated in the main scanning direction while the paper P is fed in the transport direction by the sub-scanning transport unit 30, and ink droplets are ejected from the recording head 44 to form an image. Do.
The recording head 44 uses a piezoelectric element as pressure generating means for pressurizing the ink in the ink flow path to deform the diaphragm that forms the wall surface of the ink flow path, thereby changing the volume in the ink flow path. A so-called piezo-type device that discharges droplets, or a so-called thermal-type device that discharges ink droplets with pressure generated by heating the ink in the ink channel using a heating resistor to generate bubbles. The diaphragm and the electrode that form the wall surface of the electrode are disposed opposite to each other, and the diaphragm is deformed by an electrostatic force generated between the diaphragm and the electrode, thereby changing the volume of the ink flow path and ejecting ink droplets. An electrostatic type can be used.
The paper discharge transport unit 50 includes a transport roller 51 that transports the paper P separated by the separation claw 39 of the sub-scanning transport unit 30 and a spur 52 that opposes the paper P, and a paper discharge tray 60 that is face down by reversing the paper P. A reverse roller pair 53 and a reverse paper discharge roller pair 54 are provided.

Further, a one-sheet manual sheet feeding tray 71 for manually feeding one sheet is provided on one side surface side (right side surface in FIG. 1) of the apparatus main body 1. When the single sheet feed tray 71 is lowered to the position shown in the phantom line and the sheet P is manually fed, the sheet P is guided by the upper surface of the guide plate 72 and pressurizes with the transport roller 32 of the sub-scan transport section 30. It is inserted linearly between the rollers 36.
Further, on the other side surface side (left side surface in FIG. 1) of the apparatus main body 1, a straight paper discharge tray 73 that discharges the paper P after image formation straightly face-up is provided so as to be openable and closable. By opening the straight paper discharge tray 73, the paper P sent out from the paper discharge conveyance unit 50 can be discharged straight to the straight paper discharge tray 73.
As shown in the figure, a cutting unit (means) 100 is disposed between the image forming unit 40 and the paper discharge conveying unit 50, and the sheet P on which the image is formed by the image forming unit 40 is used as necessary. After being cut by the cutting unit 100, the paper is discharged to the paper discharge tray 60 or the straight paper discharge tray 73 through the paper discharge conveyance unit 50.

Here, an example of a case (mode) in which the cutting unit 100 cuts the paper P will be described with reference to FIGS. 8 and 9 are diagrams illustrating an example of a cutting form of the paper.
As shown in FIG. 8, the first cutting mode may be a case where a plurality of sheets are obtained from one sheet. For example, after printing on A3 size paper, the center of the paper is cut to obtain two printed A4 papers.
Further, as the second cutting mode, there is a case where the paper stops in the image forming apparatus due to a jam or the like. In this case, the sheet can be easily removed by cutting.
As shown in FIG. 9, the third cutting mode includes a case where borderless printing is performed on the leading and trailing edges of the paper. For example, it is a case where a long sheet after printing is cut to obtain a printed sheet of a desired size.
These are stored in the memory or the like of the apparatus main body 1 as a “cutting mode”, and a desired operation can be performed by the image forming apparatus by designating the cutting mode from an operation unit (not shown).

The cutting unit 100 will be described. First, the basic configuration will be described with reference to FIGS. 2 is a perspective view showing a schematic configuration of the cutting unit 100, and FIG. 3 is a partially omitted perspective view drawn with the frame portion of FIG. 2 omitted.
As shown in FIG. 2, the cutting unit 100 is provided with a frame 110 that is provided over the entire width of the maximum size paper to be conveyed, and a paper that is provided over the entire width of the maximum size of paper to be conveyed, and cuts the paper by shearing force. A fixed blade 120 for moving the rotary blade, a rotary blade driving unit 130 (see FIG. 3) for moving a shuttle member, which will be described later, and a shuttle member 140 that reciprocates in the width direction orthogonal to the paper transport direction.
The frame 110 includes a rising portion 112 that slidably supports the shuttle member 140 on an upper surface portion 111 of a substantially U-shaped member. The rotary blade drive unit 130 is accommodated inside the frame 110.
The rotary blade drive unit 130 is arranged on one end side in the longitudinal direction of the frame 110 and rotates in a forward and reverse direction, a drive pulley 132 with a gear for transmitting the drive force of the drive motor 131, and the frame 110. A driven pulley 133 disposed on the other end side in the longitudinal direction, and a wire 134 wound around the driving pulley 132 and the driven pulley 133. The wire 134 is a closed loop wire, and a part thereof is fixed to the shuttle member 140. Further, a cutter sensor 135 is disposed in the vicinity of the driving pulley 132, and a cutter sensor 136 is disposed in the vicinity of the driven pulley 133. The drive motor 131 is stopped based on the ON / OFF signal of the cutter sensors 135 and 136 detected by the shuttle member 140.

Next, the shuttle member 140 will be described with reference to FIG. 4A and 4B are diagrams showing a detailed configuration of the shuttle member 140, in which FIG. 4A is a partial cross-sectional arrow view seen from the direction of arrow A in FIG. 3, and FIG. It is the partial sectional view seen from the direction.
As shown in the drawing, the shuttle member 140 includes an upper member 141 having a substantially Γ shape in cross-sectional view having a concave portion 142 that sandwiches the rising portion 112 of the frame 110, a disk-shaped moving rotary blade 150, and a moving rotary blade 150. And an accommodating portion 145 that accommodates a cleaning member 160 to be cleaned.
The accommodating part 145 is a member having a substantially stepped shape when viewed from a cross section, which is provided with a depression (step) at the top. There is a space inside the accommodating portion 145, and the bottom surface is open. Shaft hole portions 146 and 147 are formed in the lower portions of the side surfaces of the housing portion 145 facing each other, and a pivot shaft 151 serving as a pivot center of the movable rotary blade 150 is pivotally supported.
The movable rotary blade 150 is held in a state in which relative rotation is not possible and sliding is possible in the axial direction (paper conveyance direction) by inserting the central hole of the rotary hole 150 into a rotary shaft 151 that has been subjected to D-cut processing. Further, the lower end portion of the moving rotary blade 150 and the fixed blade 120 are arranged in contact with each other, and the movable rotary blade 150 is pressed against the fixed blade 120 by the urging force of the spring 152 inserted through the rotating shaft 151. Further, a rubber roller 153 having a high friction coefficient is inserted and fixed on the frame 110 side of the rotating shaft 151. The rubber roller 153 is pressed against the inner bottom 113 of the frame 110, and a frictional force is generated between them. As the shuttle member 140 reciprocates, the rubber roller 153 rotates and the moving rotary blade also rotates. In FIG. 4B, the rotation direction of the rubber roller 153 and the moving rotary blade 150 when the shuttle member 140 moves in the right hand direction in the drawing is indicated by arrows.

The cleaning member 160 includes a groove 161 that sandwiches the movable rotary blade 150, and a support hole 162 that supports the cleaning member 160 in a swingable manner. In addition, a holder 163 is supported on the ceiling portion of the accommodating portion 145 by a screw 164 on one end side in the width direction orthogonal to the paper transport direction. The cleaning member 160 is supported by the holder 163 through the support hole 162 so as to be swingable in the paper transport direction (the direction of the arrow CC in FIG. 5A). Accordingly, the cleaning member 160 moves following the movement of the moving rotary blade 150 in the paper conveyance direction.
The surface of the moving rotary blade 150 is in contact with the inner wall surface of the groove 161. When the movable rotary blade 150 rotates, the cleaning member 160 wipes off ink adhering to the surface of the movable rotary blade 150. Note that. The cleaning member 160 can be composed of, for example, a continuous porous foamed polyurethane. The wiped ink (exhaust recording agent) is deposited on the inner wall surface of the groove 161.

The cleaning of the moving rotary blade 150 by the cleaning member 160 configured as described above will be described.
When the paper P on which an image is formed in the image forming unit 40 is conveyed by the sub-scanning conveying unit 30 and reaches the cutting unit 100, the paper P enters the gap S between the frame 110 and the fixed blade 120. The paper P is temporarily stopped in a state where a portion to be cut from the downstream end of the fixed blade 120 is taken out. The shuttle member 140 moves from one end to the other end of the frame 110 by driving of the drive motor 131. At this time, the moving rotary blade 150 is pressed against the fixed blade 120 and cuts the paper P while being rotated by the frictional force generated between the inner bottom portion 113 and the rubber roller 153. While the paper P is being cut, the cleaning member 160 wipes and removes ink adhering to the movable rotary blade 150. The waste ink adheres to the cleaning member 160.
Even if the moving rotary blade 150 moves in the paper transport direction for some reason while the cleaning member 160 is cleaning the moving rotary blade 150, the cleaning member 160 follows the movement, so the moving rotary blade The positional relationship between 150 and the cleaning member 160 does not change. As a result, even if the movable rotary blade 150 moves, the cleaning performance does not deteriorate, and the movable rotary blade 150 is reliably cleaned.
As described above, according to the present embodiment, since the cutting member is provided with the cleaning member, an image due to ink adhesion that occurs during borderless printing or when the cutter blade contacts the printing surface (ink application surface) for jamming processing. Dirt or cutting failure can be prevented. At this time, since the cleaning member follows the movement of the position of the movable rotary blade, the positional relationship between the movable rotary blade and the cleaning member is kept constant, and the cleaning performance can be stabilized.

A second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a partial cross-sectional view showing the inside of the shuttle member. This embodiment is characterized in that a waste ink tank that collects the waste ink wiped off by the cleaning member is provided.
As shown in the figure, a waste ink tank 176 is disposed at the lower end of the accommodating portion 145 in the moving direction of the shuttle member 140 on one end portion side. The bottom surface 175 of the cleaning member 170 is inclined with respect to the moving direction of the shuttle member 140 so that the waste ink tank 176 side is low and the opposite side is high.
The cleaning member 170 wipes off ink adhering to the moving rotary blade 150 as the shuttle member 140 moves. Of the waste ink that has been wiped off, the amount that cannot be held by the cleaning member 170 flows along the inclination of the bottom surface portion 175 and drops into the waste ink tank 176 and is collected.
As described above, according to the present embodiment, since the waste ink removed by the cleaning member is collected in the waste ink tank, the cleaning performance can be maintained for a long time.

Next, a third embodiment of the present invention will be described with reference to FIGS. 6 is a partially omitted configuration diagram of the shuttle member, where (a) is a view seen from the direction of arrow A in FIG. 3, and (b) is a view seen from the direction of arrow D in FIG. FIG. 7 is a perspective view illustrating a schematic configuration of the cutting unit 100.
In the above-described embodiment, since the movable rotary blade is sandwiched between the cleaning members, a large force is required to rotate the movable rotary blade. In this embodiment, a gear member is attached to the rotating shaft, and the moving rotary blade is reliably rotated.
As shown in the figure, a pinion gear member 180 is inserted and fixed to the rotation shaft 151 instead of the rubber roller 153. A rack gear member 181 is provided on the inner bottom 113 of the frame 110 over the movable range of the shuttle member 140.
When the shuttle member 140 is moved by the driving force of the drive motor 131, the pinion gear member 180 is rotated by the gear meshing with the rack gear member 181 and the moving rotary blade 150 is rotated. As described above, the moving rotary blade 150 is rotated by the engagement of the gear members of the pinion gear member 180 and the rack gear member 181, so that the rotation of the movable rotary blade 150 does not stop due to an abnormality such as slip.
As described above, according to the present embodiment, since a large rotational force is obtained by using the gear member to rotate the moving rotary blade, the moving rotary blade is reliably rotated in conjunction with the movement of the shuttle member. It became possible. Therefore, it is possible to cut the sheet reliably. Furthermore, the moving rotary blade can be rotated without being affected by a disturbance that reduces the frictional force between the rack gear member and the pinion gear member.

A fourth embodiment of the present invention will be described. This embodiment is characterized in that the cleaning member, the movable rotary blade, and the fixed blade have a water repellent function.
That is, in this embodiment, the cleaning member is made of water-repellent silicon rubber so that the wiped ink is not absorbed and deposited on the cleaning member. Accordingly, the waste ink can be efficiently dropped onto the waste ink tank 176.
In addition, the surface of the moving rotary blade and the fixed blade was subjected to fluorine resin processing (water repellent treatment) to improve the water repellent performance. Thereby, it becomes difficult for ink to adhere to the surfaces of the movable rotary blade and the fixed blade, and it does not stick. Accordingly, it is possible to prevent the cutting performance from being deteriorated and to improve the ink wiping performance by the cleaning member.
The above-described embodiments can be implemented in combination. The present invention can also be applied to an electrophotographic copying machine, a copying machine, a FAX, and the like that form an image on transfer paper using toner (recording agent).

1 is a schematic configuration diagram illustrating an overall configuration of an image forming apparatus. It is a perspective view which shows a cutting part schematic structure. FIG. 3 is a partially omitted perspective view drawn with the frame portion of FIG. 2 omitted. It is a figure which shows the detailed structure of a shuttle member, (a) is the partial cross section arrow view seen from the arrow A direction of FIG. 3, (b) is one seen from the BB direction of (a). FIG. It is a partial cross section figure which shows the mode inside a shuttle member. It is a partially omitted configuration diagram of the shuttle member, (a) is a view seen from the direction of arrow A in FIG. 3, (b) is a view seen from the direction of arrow D in (a). It is a perspective view which shows schematic structure of a cutting part. It is a figure which shows an example of the cutting | disconnection form of a paper. It is a figure which shows an example of the cutting | disconnection form of a paper.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Apparatus main body, 10 ... Image reading part, 20 ... Paper feed part, 30 ... Sub-scanning conveyance part, 31 ... Conveyance belt, 32 ... Conveyance roller, 33 ... Driven roller, 40 ... Image formation part, 50 ... Discharge conveyance , 60 paper discharge tray, P ... paper, 100 ... cutting part, 110 ... frame, 111 ... upper surface part, 112 ... rise part, 113 ... inner bottom part, 120 ... fixed blade, 130 ... rotary blade drive part, 131 ... Drive motor, 132 ... drive pulley, 133 ... driven pulley, 134 ... wire, 135 ... cutter sensor, 136 ... cutter sensor, 140 ... shuttle member, 141 ... upper member, 142 ... concave, 145 ... accommodating portion, 146 ... Shaft hole, 150 ... Moving rotary blade, 151 ... Rotating shaft, 152 ... Spring, 153 ... Rubber roller, 160 ... Cleaning member, 161 ... Groove, 162 ... Support hole, 163 ... Holder, 64 ... screw, 170 ... cleaning member 175 ... bottom portion, 176 ... waste ink tank, 180 ... pinion gear, 181 ... rack gear member

Claims (4)

A transfer means for transferring the transfer material; an image forming means for forming an image on the transfer material transferred by the transfer means with a recording material; and a transfer material image-formed by the image forming means orthogonal to the transfer material transfer direction. In an image forming apparatus comprising a cutting means for cutting in the width direction,
The cutting means includes a shuttle member that reciprocates in the width direction, a moving rotary blade that is supported by the shuttle member and cuts the transfer material, and is swingably supported by the shuttle member to move the moving rotary blade. An image forming apparatus, comprising: a cleaning member that follows and removes the recording agent attached to the movable rotary blade.   The image forming apparatus according to claim 1, further comprising a waste recording agent tank that collects the recording agent removed by the cleaning member, wherein the bottom surface of the cleaning member is inclined toward the waste recording agent tank. An image forming apparatus.   The image forming apparatus according to claim 1, wherein a pinion gear member that is inserted and fixed to a rotation shaft that rotates the movable rotary blade, and a rack gear member that meshes with the pinion gear member over a movable range of the shuttle member. An image forming apparatus comprising the image forming apparatus.   4. The image forming apparatus according to claim 1, wherein the cleaning member, the movable rotary blade, and the fixed blade are provided with a water repellent function. 5.

Images