JP5564923B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus using an ink jet system such as a printer, a copying machine, and a facsimile.

  In a conventional image forming apparatus using an ink jet system, an image is formed on a recording medium using a recording head composed of a liquid ejection head that ejects droplets of recording liquid (ink). The distance between the nozzle surface of the recording head and the recording surface of the recording medium needs to be kept constant. This is because there are various thicknesses of the recording medium, and if the distance is not constant, ink cannot be printed at a target position by reciprocal printing.

  As described in Patent Document 1, in order to protect the recording head, the recording head is mounted on the carriage, and the carriage is moved up and down together with the guide rods in the main scanning direction, so that the nozzle surface of the recording head and the recording are recorded. There is an image forming apparatus that adjusts a distance from a medium. However, the carriage height adjusting mechanism used here is a system in which two guide shafts (eccentric cams) are operated by an operating lever via a link mechanism, and a required space is required as a lever swinging space. Moreover, it is not disclosed as a technique suitable for automation in that an operation lever is used.

In Patent Document 2, a holder member that holds a plurality of heads is mounted in a carriage.
The holder member is installed on a plurality of eccentric cams arranged in parallel in the carriage, and a technique is described in which the gap adjustment lever is rotated and the eccentric cams are simultaneously rotated at the same angle to raise and lower the plurality of heads for each holder. ing. However, even in this technique, although two guide shafts (eccentric cams) are connected by a rack and pinion mechanism, one guide shaft is rotated by swinging a gap adjusting lever. Although a required space is required as a lever swing space, and automation is suggested, it is based on the technology of rotating the lever, and the lever swing space is similar to the technology of Patent Document 1. As a required space is required, there remains a problem in space saving of the image forming apparatus.

  The image forming apparatuses described in Patent Documents 3 and 4 perform monochrome printing and color printing. This monochrome image forming apparatus uses monochrome and color dedicated carriages to suppress unnecessary ink consumption such as idle ejection of color ink and to protect the recording head for color printing during monochrome printing. A monochrome recording head and a color recording head are mounted on the monochrome carriage and the color carriage, respectively. In monochrome printing, only the monochrome carriage is driven and unnecessary color ink is not used. Therefore, the color recording head is protected without being driven. Further, these two carriages can be separated and connected. In an image forming apparatus, there is a demand for printing in conformity with recording media having different thicknesses. To meet this demand, the nozzle surfaces of the two recording heads of the image forming apparatus and the recording medium are used in accordance with the thickness of the recording medium. Although it is necessary to adjust the interval between them according to the paper thickness, Patent Documents 3 and 4 do not disclose a technique for adjusting the gap between the nozzle surface of the recording head and the recording medium.

  Patent Document 5 relates to a technique for engaging / disengaging a coupling portion of a toner cartridge with a driving portion of an apparatus main body. In a toner cartridge having a developer conveying member that rotates around a rotation axis, a drive transmission means that receives driving from the apparatus main body is provided. It can move in a direction substantially parallel to the rotation axis, and can take a first position that receives driving from the apparatus main body and a second position that does not receive driving from the apparatus main body. A technique relating to a toner cartridge with improved operability during mounting is disclosed. However, this technique is not related to means for moving the carriage up and down to adjust the gap between the nozzle surface of the recording head and the recording medium, and means for separating and connecting two carriages such as a monochrome carriage and a color carriage.

  As described above, according to the conventional technology, an inkjet that has a monochrome recording head, a monochrome carriage on which a color recording head is mounted, and a color carriage, and can form images corresponding to recording media having different thicknesses. In an image forming apparatus using the method, (1) a mechanism for separating and connecting two carriages performed according to image color selection, and (2) a recording medium to be used, which are necessary for image formation A mechanism for raising and lowering the recording head performed in accordance with the thickness is disclosed as an independent technique independently of each other in different patent documents. Further, there is no disclosure of specific technical means for performing the raising / lowering operation of the recording head with a driving source other than human power such as a motor. On the other hand, space saving and simplification of the apparatus configuration are desired for the image forming apparatus.

  The present invention has been made under the above circumstances, and has an individual monochrome recording head, a monochrome carriage on which a color recording head is mounted, and a color carriage, and forms an image corresponding to recording media having different thicknesses. In an image forming apparatus using an ink jet method, (1) separation and connection operations of two carriages performed according to image color selection, and (2) thickness of a recording medium to be used In addition to providing a mechanism for interlocking the connection and disconnection operation of the driving force transmission means for the raising and lowering operation of the recording head performed in accordance with the above, the entire mechanism can be controlled by associating the raising and lowering means of the recording head. The object of the present invention is to make the image forming apparatus compact and simple with a compact configuration.

In order to achieve the above object, the first means of the present invention is as follows:
A first recording head, and a first carriage having first recording head raising / lowering means for raising and lowering the first recording head and movable in the main scanning direction;
A second recording head, and a second carriage having second recording head lifting / lowering means for moving the second recording head up and down and movable in the main scanning direction;
A head lifting drive source for driving the first recording head lifting means and the second recording head lifting means;
Drive source side connection means provided integrally with the head lifting drive source;
Second recording head lifting drive connection means for the second carriage, one end of which is connected to the driving source side connection means and transmits a driving force to the second recording head lifting means;
First recording head lifting drive connecting means for a first carriage connected to the other end of the second recording head lifting drive connecting means and transmitting a driving force to the first recording head lifting means;
A connection / release means for connecting the first carriage and the second carriage and releasing the connection;
An image forming apparatus having
A first recording head lifting drive connecting means of the first carriage is connected to the other end of the second recording head lifting drive connecting means of the second carriage so that a drive for raising and lowering the head is transmitted; It has storage and connection means that can be in a storage state that is disconnected,
The storing / connecting operation of the first recording head lifting drive connecting means of the first carriage by the storing / connecting means is interlocked with the connecting / releasing operation of the first carriage and the second carriage by the connecting / release means.
The second means of the present invention is:
In the image forming apparatus described in the first means,
The connecting operation of the first recording head lifting drive connecting means and the other end of the second recording head lifting drive connecting means by the storing / connecting means is performed by the connecting / releasing means between the first carriage and the second carriage. It was decided to be done after the consolidation of.
The third means of the present invention is:
In the image forming apparatus according to the first or second means,
The first and second recording head lifting / lowering means are not moved by the operation of connecting each driving connection means for driving force input / removal to each head lifting / lowering connection / connection means and the operation of entering the storage state in which the connection is released did.
The fourth means of the present invention is:
In the image forming apparatus described in any one of the first to third means,
The first carriage can be driven back and forth in the main scanning direction, the head lifting drive source is fixed on one end side in the main scanning direction, and the second carriage and the first carriage of the first carriage from the side closer to the head lifting drive source. The second carriage is arranged in order, and the second carriage can be moved in the main scanning direction together with the first carriage by being integrally connected to the first carriage by the connecting / releasing means.
The fifth means of the present invention is:
In the image forming apparatus described in the fourth means, the second recording head lifting drive connecting means integrated with the second carriage approaches the head lifting drive source to a position where it is connected to the driving source side connecting means. The position is the home position of the second carriage,
A position where the first carriage is close to a position where it can be connected by the connecting / releasing means with respect to the second carriage positioned at the home position is defined as a home position of the first carriage.
With the first carriage and the second carriage in their respective home positions, the storage / connection operation of the head lifting drive connection means of the first carriage by the storage / connection means and the connection / release means by the connection / release means. The connection / release operation of one carriage and the second carriage can be performed.
The sixth means of the present invention includes
In the image forming apparatus according to any one of the first to fifth aspects,
The first recording head lifting / lowering means holds the first recording head and is restricted in the moving direction only in the lifting / lowering direction and supported in the first carriage;
Elastic means for urging the head holder in the up and down direction;
A slide having a rack that supports the head holder biased by the elastic means and is supported by the first carriage so as to be reciprocally movable in the sub-scanning direction, and has a streak direction formed at one end thereof in the main scanning direction. With cam,
A pinion meshing with the rack;
Have
The pinion is configured to be coaxial with the first recording head lifting drive connecting means.
The seventh means of the present invention is:
In the image forming apparatus according to any one of the first to sixth aspects,
The second recording head lifting / lowering means holds the second recording head and is restricted in the moving direction only in the lifting / lowering direction and supported in the second carriage,
Elastic means for urging the head holder in the up and down direction;
A slide having a rack that supports the head holder urged by the elastic means and is supported by the second carriage so as to be reciprocally movable in the sub-scanning direction, and has a streak direction formed in the main scanning direction at one end thereof. With cam,
A pinion meshing with the rack;
Have
The pinion is configured to be coaxial with the second recording head lifting drive connecting means.
The eighth means of the present invention is:
In the image forming apparatus according to any one of the first to seventh aspects,
The storing / connecting means includes:
A support shaft that coaxially holds the pinion and the first recording head lifting drive connection means;
A support means for supporting the first carriage by the first carriage so that the axis of the support shaft is aligned with the main scanning direction, and is movable and rotatable in the main scanning direction;
A storage guide as a cam follower attached to the support shaft;
Biasing means for biasing the pinion, the first recording head lifting drive connecting means, the support shaft, and the storage guide so as to move in a direction approaching the second recording head lifting drive connecting means;
A storage cam that contacts the storage guide to prevent the biasing means from moving the support shaft and to switch the first recording head lifting drive connection means between a connected state and a stored state according to rotation;
And a storage cam drive source for rotating the storage cam.
The ninth means of the present invention includes
In the image forming apparatus according to any one of the first to eighth aspects,
The connecting / releasing means is
A connecting member that is displaced to a position where the first carriage and the second carriage are integrally connected by a reciprocating operation and a position where the integrated connection is released, and a connecting member drive that displaces the connecting member. Consisting of mechanism,
The connecting member drive mechanism
Guiding means for regulating the direction of reciprocation of the connecting member;
A rack formed on the connecting member;
A pinion that meshes with the rack and reciprocates the connecting member by rotation thereof;
A gear drive source for rotating the pinion,
This gear drive source is shared with the storage cam drive source that drives the storage / connection means.
The tenth means of the present invention includes
In the image forming apparatus according to the ninth means,
After the connection between the first carriage and the second carriage by the connecting / releasing means, the first recording head lifting drive connecting means by the storing / connecting means and the other end of the second recording head lifting drive connecting means; The relationship between the contact position in the rotational direction of the storage cam that contacts the storage guide and the meshing position of the pinion in the reciprocating direction of the rack formed on the coupling member It was decided that.

According to the first aspect of the present invention, in an image forming apparatus using an ink jet system, (1) separation / connection operation of two carriages performed according to image color selection, and (2) use required for image formation Provide a mechanism that interlocks the connection and disconnection operation of the driving force transmission means for raising and lowering the recording head that is performed according to the thickness of the recording medium to be performed, and also relates the raising and lowering means of the recording head As a result, the overall mechanism can be made compact, and the image forming apparatus can be made small and simple.
According to the second aspect of the present invention, after the first carriage and the second carriage are integrally connected, the connection operation between the first recording head lifting drive connecting means and the second recording head lifting drive connecting means is performed. The drive connection of the connection and the head raising / lowering is stable, and there is no influence on the accuracy of the coupling position between the first carriage and the second carriage and the positional relationship between the recording heads of both carriages.
In the third aspect of the invention, the first and second recording head lifting / lowering means do not move due to the connection operation of each driving connection means for driving force input to each head lifting / lowering driving connection means and the storing operation for connection release. The position of each recording head in the elevation direction within the carriage is stable.
According to the fourth aspect of the present invention, in image formation using both the first carriage and the second carriage, the second carriage is integrated with the first carriage, so that the image writing accuracy is stabilized.
According to the fifth aspect of the present invention, both the first carriage and the second carriage perform the connection and release of the two carriages and the raising and lowering of the recording head at a predetermined home position, so that the apparatus configuration can be simplified.
According to a sixth aspect of the present invention, the pinion meshing with the rack of the first recording head lifting / lowering means is coaxial with the first recording head lifting / lowering driving / connecting means. In the storing / connecting operation, the pinion moves in the rack direction along with the first recording head lifting / lowering connecting means, so that the lifting / lowering operation of the first recording head lifting / lowering means is not affected. Get the effect.
According to a seventh aspect of the present invention, the drive source side drive connection means provided integrally with the head lift drive source is provided, wherein the pinion meshing with the rack of the second print head lift means is coaxial with the second print head lift drive connection means. When the second recording head lifting drive connecting means of the second carriage is connected, the pinion moves in the direction of the rack of the rack together with the second recording head lifting drive connecting means. The operation is not affected and the same effect as that of claim 3 is obtained.
According to the eighth and tenth aspects of the present invention, the timing of switching the first recording head lifting drive connecting means between the connected state and the stored state is adjusted according to the rotational position of the storage cam, and the head lifting / lowering of the first carriage by the storing / connecting means is performed. Adjustment is easy so that the storage / connection operation of the drive connection means and the connection / release operation of the first carriage and the second carriage by the connection / release means are appropriately performed.
In the ninth and tenth aspects of the present invention, the connecting member is reciprocated by the rack and the pinion, and by adjusting the meshing position of the rack and the pinion, the head lifting / lowering of the first carriage by the storing / connecting means is performed. Adjustment is easy so that the storage / connection operation of the drive connection means and the connection / release operation of the first carriage and the second carriage by the connection / release means are appropriately performed.

It is a perspective view of a recording device. 1 is a schematic plan view of a recording apparatus. 1 is a schematic plan view of a recording apparatus. 1 is a schematic plan view of a recording apparatus. 1 is a schematic plan view of a recording apparatus. FIG. 3 is a perspective view of a first recording head and a first head holder. FIG. 6 is a perspective view showing a relationship in which the first recording head is accommodated in the first head holder. FIG. 6 is a perspective view showing a state in which the first recording head is accommodated in the first head holder. FIG. 6 is a schematic view of the first carriage 5 as viewed from the side (main scanning direction X1-X1) when the paper thickness is thin. FIG. 5 is a schematic view of the first carriage 5 as viewed from the side (main scanning direction X1-X1) when the paper thickness is thick. The schematic diagram which looked at the 1st carriage 5 from the front (sub scanning direction Y1-Y1) is shown, (a) is a case where paper thickness is thin, (b) is a case where paper thickness is thick. The figure which looked at the 1st carriage 5 from the upper direction (sub-scanning direction Y1-Y1) is shown. It is a perspective view of a slide cam and a pinion. FIG. 4 is a schematic view of the first carriage 5 as viewed from the front (sub-scanning direction Y1-Y1), where (a) shows no contact between the cam of the first head holder and the cam of the slide cam, and (b) shows the first head holder. It is the figure explaining the case where this cam and the cam of a slide cam are contact. (A), (b) is the perspective view demonstrated with the pinion which attaches the specific example of a connection means. It is a perspective view of a storage and connection means. It is a perspective view of a storage / connection means and a connection member drive mechanism. It is a fragmentary sectional front view of a storage and a connection means and a connection member drive mechanism. (A) is a partial cross-sectional front view of a storage / connection means and a connection member drive mechanism, (b) is a partial front view of two connected joints. (A) is a partial cross-sectional front view of a storage / connection means and a connection member drive mechanism, (b) is a partial front view of two connected joints. (A) is a partial cross-sectional front view of a storage / connection means and a connection member drive mechanism, (b) is a partial front view of two connected joints.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, the same number is attached | subjected to the process which performs the structure part which has the same function, and the same process, and duplication description is abbreviate | omitted.
The image forming apparatus 1000 according to the present exemplary embodiment can be roughly divided into a recording apparatus 100 and a paper feeding unit. The recording apparatus 100 mainly includes a mechanism that forms an image by ejecting ink onto a recording medium (for example, paper) by an inkjet recording head, and the paper feeding unit mainly includes a mechanism that conveys the recording medium to the recording apparatus.

[Overview of overall configuration of recording device]
A perspective view of the image forming apparatus 1000 and the recording apparatus 100 is shown in FIG. 1, and a schematic view of the recording apparatus 100 as viewed from above is shown in FIG. Although not shown, the paper feeding unit is incorporated in the main body of the recording apparatus 100. Alternatively, the recording apparatus 100 may be connected as a separate apparatus. In this example, two types of sheets having different thicknesses are used as recording media, and these two types of sheets are selectively switched and conveyed to the recording apparatus 2 to form an image.

  In the following description, the distance between the nozzle surface of the recording head and the recording surface of the recording medium is referred to as a gap L, and the axial longitudinal direction of the guide rod 1 that is the direction in which the recording head moves is referred to as the main scanning direction X1-X1. A direction orthogonal to the main scanning direction X1-X1 on an arbitrary virtual plane showing the main scanning direction X1-X1 is referred to as a sub-scanning direction Y1-Y1, and the main scanning direction X1-X1 and the sub-scanning direction Y1-Y1 are A direction perpendicular to an arbitrary virtual plane shown is referred to as an up-down direction Z1-Z1. In the recording apparatus 100, the sub-scanning direction Y1-Y1 is the recording medium feeding direction, the vertical direction Z1-Z1 is the vertical direction of the recording head, and the gap L is the distance in the vertical direction Z1-Z1.

  The ink jet recording apparatus 100 is a serial type ink jet recording apparatus, and includes a recording apparatus and a support base 160 that supports the recording apparatus. Inside the recording apparatus 100, the guide rod 1 and the sub guide 2 are stretched over and fixed to the left side plate 3 and the right side plate 4. The monochrome carriage 5 as the first carriage has a cylindrical guide rod 1 for scanning and a bearing portion 14 that slides at both ends in the main scanning direction X1-X1.

  The color carriage 6 that is the second carriage does not move independently, and the first carriage 5 is integrally connected to the second carriage 6 by the connecting member 49 provided on the first carriage 5 side as shown in FIG. It can move in the main scanning direction X1-X1 together with one carriage. Because of the movement method in such a connected state, if a bearing portion is also provided in the color carriage 6 for the guide rod 1, so-called twisting may occur due to the relationship with the bearing portion 14 of the monochrome carriage 6. In order to avoid this, the guide There is no bearing that fits the entire rod 1. However, since the guide rod 1 is slid while being supported by a load, there is a load support portion 14 ′ that fits loosely on a flat plate interposed between the guide rod 1 and the guide rod 1.

  A long plate-shaped sub guide 2 is fixed between the right side plate 3 and the left side plate 4, and the end portion of the first carriage 5 in the sub scanning direction Y 1 -Y 1 has the sub guide 2. A guide portion 16 composed of two rollers is arranged so as to sandwich the flat plate surface of the guide 2 from both sides. The first carriage 5 is held by the bearing portion 14 and the guide portion 16 so as to be slidable in the main scanning direction (X1-X1 direction). A guide portion 16 ′ similar to the guide portion 16 is also arranged at the end of the second carriage 6 in the sub-scanning direction Y 1 -Y 1.

  FIG. 2 shows a state in which the first carriage 5 and the second carriage 6 are connected to each other by the connecting member 49 and are moved halfway in the main scanning direction X1-X1. The first carriage 5 and the second carriage 6 are moved together when forming a full-color image.

  FIG. 3 shows a state in which the first carriage 5 and the second carriage 6 are connected by the connecting member 49 and moved to the right end in the main scanning direction X1-X1 in the guide rod 1, and this position is the first position. These are the home positions for the first carriage 5 and the second carriage 6.

  FIG. 4 shows a state in which the second carriage 6 is at the home position and only the first carriage 5 is moved to the middle in the main scanning direction X1-X1 in the guide rod 1, and thus the second carriage 6 Is left in the home position, and only the first carriage 5 is moved in the main scanning direction X1-X1 when a monochrome image is formed.

  FIG. 5 shows a state in which the first carriage 5 and the second carriage 6 are not connected by the connecting member 49 and both the carriages are separated from their home positions. The maintenance mechanism 8 and the driven pulley 122, which are not visible when both carriages are at the home position, are clearly shown so that the structure can be easily understood.

  As shown in FIGS. 1 to 5, in this example, the first carriage 5 is mounted with two first recording heads 71 and 72 that eject black (K) ink droplets. The second carriage 6 is equipped with second recording heads 73, 74, and 75 that discharge ink droplets of yellow (Y), magenta (M), and cyan (C) colors. The two first recording heads 71 and 72 are arranged with their positions shifted in the main scanning direction and the sub-scanning direction, respectively. Each of the recording heads 71, 72, 73, 74, and 75 is integrally provided with a sub tank that supplies ink to each of the recording heads 7 (not shown).

  As shown in FIG. 6, the first recording heads 71 and 72 are accommodated in the first head holder 27, and further, the first head holder 27 on which the first recording heads 71 and 72 are mounted as shown in FIG. Is mounted on the first carriage 5.

  Similarly, the second recording heads 73 to 75 shown in FIGS. 2 to 5 are accommodated in a second head holder (not shown, but the structure conforms to that of the first head holder 27). It is mounted on the second carriage 6. 3 to 5, the first head holder 27 and the second head holder are omitted. The assembly structure of the recording head and the head holder in the carriage will be described later.

  Referring to FIGS. 1 and 2 to 5, the main scanning mechanism that moves and scans the first carriage 5 and the second carriage 6 is disposed on one side (left end portion) of the recording apparatus 100 in the main scanning direction X1-X1. The main scanning motor 9, the driving pulley 121 fixed to the rotation shaft of the main scanning motor 9, the driven pulley 122 arranged on the other side (right end) in the main scanning direction, and hung between these pulleys. And a timing belt 10. The driven pulley 122 is biased outward (on the right side plate 4 side) by a spring tensioner 13 to apply tension to the timing belt 10.

  A part of the timing belt 10 is fixedly held by a belt holding portion 15 provided on the back side of the first carriage 5, whereby the first carriage 5 is driven by the main scanning driving force from the main scanning motor 9. At the same time, it can reciprocate in the main scanning direction X1-X1. The guide rod 1 and the sub guide 2 are movable in the main scanning direction X1-X1. The second carriage 6 is integrally connected to the first carriage 5 by a connecting member 49 and is movable in the main scanning direction X1-X1.

  An encoder sheet 11 for detecting the position of the first carriage 5 in the main scanning direction X1-X1 (the position of the first recording heads 71 and 72) is provided on the back side of the first carriage 5 in the main scanning direction. Arranged along X1-X1. The first encoder sensor 17 provided on the back side of the first carriage 5 can detect the main scanning position of the first carriage 5 by reading the encoder sheet 11.

  The connecting member 49 can reciprocate in the vertical direction Z1-Z1, and a connecting member receiving portion formed by using each of the side plate of the first carriage 5 and the side plate of the second carriage 6 in the lowered position. The first carriage 5 and the second carriage 6 are integrally connected by sandwiching them in the overlapped state at the same time. Further, the connection is released from the connecting member receiving portion at the raised position, and the first carriage 5 and the second carriage 6 are separated from each other. The connecting member 49 is driven to be displaced by a connecting member driving mechanism 181 as connecting / releasing means formed on the first carriage 5. 4 and 5 show the connecting member receiving portion 182 of the second carriage 6. The first carriage 5 and the second carriage 6 are connected by the connecting mechanism 181 and the connecting member 49, and the second carriage 6 is pulled by the driving force from the main scanning motor 9 transmitted to the first carriage 5. The main carriage 5 and the second carriage 6 are integrally driven. Details of the connecting / releasing means including the connecting member 49 and the connecting member driving mechanism 181 will be described later.

[Power transmission system to the recording head lifting means]
In the recording apparatus 100 of this example, the recording head is moved up and down so that the distance between the recording head and the surface of the recording medium is constant according to the thickness of the recording medium to be used. In the example of the plan view shown in FIGS. 2 to 5, a head lifting drive source (motor) 20 that is a drive source of the recording head lifting means is disposed on the outer wall of the right side plate 4 and is close to the head lifting drive source 20. The second carriage 6 and the first carriage 5 are arranged in this order.

  A drive source joint 19 is provided on the rotary shaft of the head lifting drive source 20 as drive source side drive connection means. The second carriage 6 is pivotally supported by the second recording head lifting drive connection means 18 in the main scanning direction X1-X1. The second recording head lifting drive connecting means 18 has a second carriage right joint 18R at one end (right end) and a second carriage left joint 18L at the other end (left end), and these second carriage right joint 18R. The second carriage left joint 18L is connected by a drive transmission shaft 18J.

  When the second carriage 6 is located at the home position, the second carriage right joint 18R is connected to the drive source joint 19, and the pinions 18R and P formed coaxially with the second carriage right joint 18R serve as the second recording head. By engaging with the rack 24RC of the lifting / lowering means 600, the driving force is transmitted to the second recording head lifting / lowering means 600R. The second recording head lifting / lowering means 600R to which the driving force is transmitted has a second head holder holding the second recording heads 73, 74, and 75 (the configuration is similar to the first head holder 27 shown in FIG. Is moved up and down on the second carriage 6. The second carriage left joint 18L located at the left end of the second recording head lifting drive connecting means 18 is integrated with the second carriage right joint 18R via the drive transmission shaft 18J, and the second carriage left joint 18L. The pinions 18L and P formed integrally with the second gear are engaged with the rack 24RC of the second recording head lifting / lowering means 600L, and similarly the second recording head lifting / lowering means 600L is driven to move the second carriage 6 up and down. The second recording heads 73, 74, and 75 are held together with the second head holder by the two right and left second recording head lifting / lowering means 600R and 600L at an appropriate height position corresponding to the thickness of the recording medium to form an image. Is called.

  As apparent from FIGS. 2 to 5, the drive source joint 19 and the second carriage right joint 18R are connected only in the case of FIGS. 3 and 4 in which the second carriage 6 is in its home position. In such a home position, the heights of the second recording heads 73, 74, 75 are adjusted.

  In order for the first recording heads 71 and 72 (first head holder 27) to move up and down, as shown in FIG. 3, the first carriage 5 and the second carriage 6 are positioned at the home position, and the two carriages are connected. It is necessary to be integrally connected by the member 49.

  The first carriage 5 has a first carriage right joint 23R which is a joint constituting a part of the first recording head raising / lowering drive connecting means, and a drive transmission shaft (support shaft) whose longitudinal axis is aligned with the main scanning direction X1-X1. 26 is supported (fixed) at the right end portion of 26. A pinion 23 </ b> L / P is supported (fixed) at the left end of the drive transmission shaft 26. On the outer periphery of the first carriage right joint 23R, pinions 23R and P are provided coaxially with the first carriage right joint 23R.

  The drive transmission shaft 26 is provided with storage / connecting means 41 to be described later. The storage / connection means 41 connects the drive transmission shaft 26 integral with the first carriage right joint 23R and the pinions 23L / P to the main scanning direction X1. -Has a function of reciprocating in X1. The storage / connecting means 41 causes the drive transmission shaft 26 to move rightward in a state where the first carriage 5 and the second carriage 6 are integrally connected by the connecting member 49. As a result, the first carriage right joint 23R and the second carriage left joint 18L are engaged with each other, and the driving force of the head lifting drive source 20 is supplied to the first carriage right joint via the second recording head lifting drive connection means 18. 23R (coaxial pinion 23R · P) and pinion 23L · P.

  The racks 24RC of the first recording head lifting / lowering means 500R on the side closer to the second carriage 6 and the first recording head lifting / lowering means 500L on the side farther from the second carriage 6 are provided on these pinions 23R · P and 23L · P. 11, 12, and 13), the first recording heads 71 and 72 are moved up and down on the first carriage 5 together with the first head holder 27 by the rotation of the pinions 23R · P and 23L · P. The image is formed while being held at an appropriate height position corresponding to the thickness of the recording medium. The first recording head lifting / lowering means 500R and 500L will be described in detail in the section [Recording head lifting / lowering means] together with FIGS.

  As described above, in the second carriage 6, the racks 24RC, the second carriage right joint 18R, and the second carriage left joint 18L in the second recording head lifting / lowering means 500R and 500L are coaxially connected with the pinions 18R · P and 18L · P. Due to the meshing relationship, the first recording heads 73 to 75 are moved up and down together with the head holder and held at an appropriate height position corresponding to the thickness of the recording medium, thereby forming an image. However, in the second carriage 6, the drive transmission shaft 18J does not slide, and no means corresponding to the storage / connection means 41 is provided.

  When the first recording head elevating means 500R, 500L does not raise or lower the first recording head, the storage / connection means 41 moves the drive transmission shaft 26 to the left so that the first carriage right joint 23R becomes the second carriage left. It is retracted and stored in a position separated from the joint 18L and in a non-engagement state. In particular, as shown in FIG. 4, when the first carriage 5 is moved toward the home position with respect to the second carriage 6 at the home position, the claw portion for meshing the first carriage right joint 23R is assumed. Projecting to a position where it can engage with the claw portion of the second carriage left joint 18L, the claw portions of these joints are not connected to each other in a state where the first carriage 5 and the second carriage 6 are integrally connected by the connecting member 49. This is because the meshing affects the position accuracy of the carriage and impairs the accuracy of image formation.

  For this reason, the first carriage right joint 23R is movable in the main scanning direction X1-X1 and the storage / connection means 41 is provided to store and connect the first carriage right joint 23R. The direction of the teeth of the pinion 23R / P and the first carriage pinion 23L / P provided coaxially with the first carriage right joint 23R, and the slide cam with which the pinions 23R / P and 23L / P are engaged are integrally formed. Since the direction of the streaks of the rack 24RC is parallel to the main scanning direction, the rack 24RC that meshes with the pinions 23R / P and 23L / P is not operated in the storing / connecting operation. It does not affect the raising and lowering (see FIGS. 11, 12, and 13 described later).

[Maintenance mechanism of recording head at home position]
Of the main scanning areas in which the first carriage 5 and the second carriage 6 can move in the main scanning direction, the recording medium 150 is shown in FIG. The paper is not transported intermittently in the sub-scanning direction Y1-Y1 by the paper feeding mechanism. Further, one end side of the main scanning area, that is, the right end area in this example, is the home position of both carriages, and a maintenance mechanism 8 for maintaining and recovering the recording heads 71 to 75 is disposed. The maintenance mechanism 8 is means for opening and closing the caps of the ink cartridges of the recording heads 71 to 75. By closing the cap, each recording head is integrated with the main body of the recording apparatus 100, and is positioned and fixed integrally with the main body. The

  As shown in FIG. 4, when only the first carriage 5 is driven in the main scanning direction X 1 -X 1 without connecting the first carriage 5 and the second carriage 6, the second carriage 6 moves to the maintenance mechanism 8. The cap is closed and the position is maintained. As described above, the second recording heads 73 to 75 of the second carriage 6 can be kept in a protected state, and the life of the second recording heads 73 to 75 of the second carriage 6 can be extended. By placing the cap in the closed state, it is possible to suppress wasteful color ink consumption during monochrome printing.

[Power transmission system to the recording head lifting means]

  With respect to the second carriage 6, power is transmitted from the head lifting drive source 20 via the drive source joint 19, the second carriage right joint 18R, and the second carriage right joint 18L, and the second recording head lifting means 600 is driven. The second head holder on which the second recording heads 73, 74, and 75 are mounted is moved up and down on the second carriage and held at an appropriate height position corresponding to the thickness of the recording medium, thereby forming an image.

  The first carriage 5 is engaged with the second carriage right joint 18L to transmit power to the first carriage right joint 23R, and the pinions 23R · P and 23L · P that are coaxially integrated with the first carriage right joint 23R are also included. When driven, the corresponding first recording head elevating means 500R and 500L are driven up and down to be held at an appropriate height position according to the thickness of the recording medium, thereby forming an image.

  In the recording apparatus of this example that can cope with paper types having different paper thicknesses, a head raising / lowering means is provided to adjust the height of the recording head, and the first carriage 5 and the second carriage 6 are provided separately. Therefore, the connection and release between the carriages by the connecting member are performed in accordance with the switching between the color image and the monochrome image. Also, in order to avoid the influence on the positional relationship between the recording heads of both carriages due to the force received when the claws of both joints are engaged when the joints that are power transmission means to the head lifting means are connected, the connection of both joints is avoided. Is performed in a state where the carriages are integrated by the connecting member. For this reason, it is necessary to connect and release the joints when both the carriages are connected, and (a) the joints between the joints and (b) the connection / release of the carriages by the connecting member are released. These timings are related to each other so that both joints can be connected and separated under the connected state. Further, in this example, since power is transmitted to the lifting / lowering means with both carriages in the home position, each operation of the storage / connection means, connection / release means and lifting / lowering means with both carriages in the home position. Is done.

  In the image forming apparatus using the recording apparatus 100 of this example, the first carriage 5 alone, or the one in which the first carriage 5 and the second carriage 6 are connected is moved in the main scanning direction X1-X1, and the recording medium is moved to the auxiliary medium. While intermittently feeding in the scanning direction Y1-Y1, the corresponding recording heads of the first and second recording heads 71 to 75 are driven in accordance with the image information to discharge droplets, thereby causing a required recording medium. An image is formed.

[Assembly structure of recording head, head holder and carriage]
An assembly structure of the first recording heads 71 and 72 and the first head holder 27 in the first carriage 5 will be described. Since the second recording heads 73 to 75 and the assembly structure of the second recording heads 73 to 75 in the second carriage 6 are the same as the relationship with the second carriage 6, illustration and description thereof are omitted.

  As outlined above, FIG. 6 shows a perspective view of the first recording heads 71 and 72 and the first head holder 27, and FIG. 7 shows the first recording heads 71 and 72 as the first head holder 27 (head holder assembly). FIG. 8 is a perspective view showing a state in which the first recording heads 71 and 72 are accommodated in the first head holder 27.

  As shown in FIG. 6, each of the first recording heads 71 and 72 has rectangular convex portions 71A and 71B whose bottom portions are slightly smaller than the head body portion having a rectangular parallelepiped shape at the top thereof, and the bottom surfaces of the first recording heads 71 and 72 have first nozzles. The surfaces 71a and 72a are referred to. The first head holder 27 has a substantially rectangular parallelepiped shape and has a box shape with an upper opening, and the box-shaped recess serves as a head holder accommodating portion 27 a for accommodating the first head holder 27.

  The first head holder 27 has a shape in which the front (front side facing the operator) of the two side walls 27c on both sides in the longitudinal direction (sub-scanning direction Y1-Y1) is cut off. Further, two rectangular head holder holes 27 b are formed at the bottom of the first head holder 27. When the two first recording heads 71 and 72 are accommodated in the head holder accommodating portion 27a by fitting the rectangular convex portions 71A and 71B into the respective holder holes 27b, the first first recording heads 71 and 72 are respectively received from the two head holder holes 27b. The nozzle surfaces 71a and 72a are exposed (see FIGS. 9, 10, 11, and 14). Since the two head holder holes are formed so as to be shifted in the sub-scanning direction Y1-Y1, the substantial length of the recording head in the sub-scanning direction is increased and the scanning area of the monochrome image is widened.

  The two side walls 27c of the first head holder 27 are formed with head holder convex portions 27d protruding in the main scanning direction Z1-X1 along the longitudinal direction (sub-scanning direction Y1-Y1). The lower surface of the head holder convex portion 27d has a head holder cam surface 27e (uneven surface) that is uneven in the vertical direction Z1-Z1. The role of the head holder cam surface 27e will be described later.

  As shown in FIG. 8, the first head holder 27 that houses the first recording heads and the first recording heads 71 and 72 is moved up and down by the first recording head lifting means 500R and 500L, and the second recording heads 73, 74, and 75 are housed. The second head holder (not shown) is raised and lowered by the second head lifting means 600R and 600L.

  The first carriage 5 will be described with reference to FIGS. The first carriage 5 is open at the top and has a box shape that is long in the sub-scanning direction Y1-Y1. The box-shaped bottom portion has a step portion 5a, and the first head holder 27, the storage / connection means 41, the first recording head elevating means 500R, 500L, etc. are accommodated in the bottom portion on the front side of the step portion 5a. There is a bottom region 5b.

  A carriage hole 5c is formed at the center of the bottom region 5b, leaving the bottom in all directions. The carriage hole 5c is large enough to accommodate the bottom of the first head holder 27. The first head holder 27 faces the carriage hole 5c, and peripheral members attached to the first head holder 27 are assembled. It is done. In this assembled state, the nozzle surfaces 71a and 72a of the two recording heads 71 and 72 on the first head holder 27 are exposed from the carriage hole 5c. The first carriage 5 is provided with a first encoder sensor 17, a bearing unit 14, a belt holding unit 15 and the like for detecting the positions of the carriage and the recording head.

  The first head holder 27 containing the first recording heads 71 and 72 can be moved up and down in the vertical direction Z1-Z2 by the first head lifting means 500R and 500L. Similarly, in the second carriage 6, the second head holder that accommodates the second recording heads 73 to 75 can be moved up and down in the height direction Z1-Z2 by the second head lifting means 600R, 600L. As the first recording heads 71 and 72 and the second recording heads 73 to 75 are moved up and down, the first nozzle surfaces 71a and 72a of the first recording heads 71 and 72 and the second nozzle surfaces of the second recording heads 73 to 75 and The gap L with respect to the printing surface of the recording medium can be adjusted to a constant distance regardless of the thickness of the recording medium due to the difference in paper type.

  The gap L to be adjusted is determined by the user visually checking the thickness of the recording medium and inputting the value of the gap L according to the thickness of the recording medium from an input unit (not shown). It can be adjusted by driving the lifting means. Alternatively, when image data on a PC (personal computer) terminal is transmitted to the image forming apparatus 1000 for printing, the user inputs the thickness of the recording medium into the PC terminal and The gap L may be measured, and the measured gap L may be transmitted to the image forming apparatus 1000 together with the image data to adjust the gap L in the same manner. Further, the gap L corresponding to the thickness can be calculated and adjusted using a known technique in which the image forming apparatus 1000 automatically measures the thickness of the recording medium. With this configuration, the user does not need to obtain the thickness of the recording medium.

[Recording head lifting means]
Next, the first recording head lifting / lowering means 500R and 500L will be described. The second recording head lifting / lowering means 600R and 600L have the same configuration as the first recording head lifting / lowering means 500R and 500L, and thus illustration and description thereof are omitted. In this example, the first head raising / lowering means 500R, 500L uses an uneven cam mechanism that is a combination of slopes on the plate surface of an elongated rectangular parallelepiped, but other cam mechanisms and other mechanisms that can raise and lower the first head holder 27. Other mechanisms may be used as long as they are present.

  9 and 10 are schematic views of the first carriage 5 viewed from the side (main scanning direction X1-X1), and FIG. 11 is a schematic view of the first carriage 5 viewed from the front (sub-scanning direction Y1-Y1). FIG. 12 is a schematic plan view of the first carriage 5 as viewed from above, and FIG. 13 is a perspective view of the slide cam 24.

  As shown in FIGS. 9 to 11, on the side wall portion 5d formed on the first carriage 5 so as to face both sides of the main scanning direction X1-X1 along the longitudinal direction (sub-scanning direction Y1-Y1). A convex spring pressing portion 50 is formed along the longitudinal direction.

  In addition, guide members (in the four side portions of the head holder 27) that make the head holder 27 movable only in the vertical direction Z1-Z1 and restrict movement in the main scanning direction X1-X1 and the sub-scanning direction Y1-Y1. (Not shown) are in contact with each other so as to be close or slidable.

  A holder cam surface 27e is formed on the lower surface of the cam projection 27d provided on the side of the head holder. The holder cam surface 27e constitutes a cam including a plurality of convex portions 27eM projecting downward, and concave portions 27eV formed adjacent to the convex portions 27eM and the convex portions 27eM via the slope SU. The top part of the convex part 27eM and the bottom part of the concave part 27eV form a flat surface parallel to the X1-Y1 plane of orthogonal coordinates.

  Two slide cams 24 are arranged in parallel below the two cam projections 27d and in the bottom region 5b of the carriage 5 so as to face each cam projection 27d. The slide cam 24 is guided by a rail (not shown) and regulated in the sub-scanning direction Y1-Y1, and can move and reciprocate in the longitudinal direction of the second carriage 5 (sub-scanning direction Y1-Y1). The slide cam 24 and the drive transmission shaft 26 are arranged so that the rack 24RC and the pinion 23R · P and the rack 24RC and the pinion 23L · P are engaged and orthogonal to each other. The first carriage right joint 23R is rotated integrally with the joint 23R and the drive transmission shaft 26 when the driving force from the head lifting drive source 20 is transmitted. When the drive transmission shaft 26 is rotated, the two parallel slide cams 24 are moved in the sub-scanning direction Y1- due to the engagement between the rack 24RC and the pinions 23R and P, and the mesh between the rack 24RC and the pinions 23L and P. Move back and forth in Y1.

  A plurality of convex portions 24eM projecting upward in a region facing the holder cam surface 27e on the upper surface of the slide cam 24, and the convex portions 24eM and the concave portions 24eV formed adjacent to the convex portions 24eM via the slope SD. Is formed. The top part of the convex part 24eM and the bottom part of the concave part 24eV form a flat surface parallel to the X1-Y1 plane of orthogonal coordinates.

  On the upper surface of the end portion of the slide cam 24 on the back side (side near the sub guide 2) in the sub scanning direction Y1-Y1, the direction of the tooth trace is a rack 24RC in the main scanning direction. As shown in FIGS. 11, 12, and 13, the rack 24RC of the first recording head lifting / lowering means 500R engages with the coaxial first pinion 23R / P integrated with the first carriage right joint 23R, and the first recording head lifting / lowering means. A pinion 23L / P meshes with the 500L rack 24RC.

  The drive source joint 19 and the second carriage right joint 18R mesh with each other, the second carriage left joint 18L and the first carriage right joint 23R mesh with each other, and the head lifting drive source 20 is driven to drive the pinions 23L and P and the pinion. 23R · P rotates and the slide cam 24 is moved in the sub-scanning direction Y1-Y1 together with the rack 24RC. With this movement, the cams (projections 24eM, recesses 24eV) of the slide cam 24 are moved to the head holder projection 27d. The position of the first head holder 27 is raised and lowered by changing the position with respect to the cam (the convex portion 27eM and the concave portion 27eV).

  An extensible spring 31 as an elastic means for urging the first head holder 27 in the vertical direction is provided between the upper surface of the cam projection 27d provided on the side of the first head holder 27 and the spring pressing portion 50. It is installed. The first head holder 27 is urged downward by the elasticity of the spring 31, and the downward movement of the first head holder 27 by this urging force is caused by the movement of the slide cam 24 in the sub-scanning direction Y1-Y1 ( It is blocked by entering either state 1) or (2).

(1): As shown in FIGS. 9 and 11A, the cam convex portion 27eM formed on the lower surface of the cam convex portion 27d and the cam concave portion 24eV formed on the slide cam 24 face each other, and the inclined surface In the state where SD and the slope SU face each other, the first head holder 27 is lowered to the lowest position, and the bottom of the first head holder 27 is positioned in the positioning region 60 disposed in the bottom region 5 b of the first carriage 5. Is positioned in the vertical direction in a state in which the elastic force of the spring 31 is received.

  In this case, as clearly shown in FIG. 14A, the convex portions 27eM and the concave portions 27eV formed on the lower surface of the cam convex portion 27d are formed on the slide cam 24 so that the accurate positioning function by the positioning member 60 is fulfilled. The height is set so that a gap D is provided between the cam convex portion 27d and the slide cam 24 so that neither the convex portion 24eM or the concave portion 24eV formed in the above is in contact. The positioning member 60 is disposed in the bottom region 5b so as to support the first head holder 27 at three points so as to be in contact with the first head holder 27 and to stabilize the positioning state.

  This example is a case where the first recording heads 71 and 72 are closest to the recording medium reference plane OO, and is applied when the recording medium 150 sent along the recording medium reference plane OO is thin paper, The gap L between the first nozzle surfaces 71a and 72a and the recording medium 150 is set to a predetermined constant value.

  Here, assuming that the state in which the inclined surface SD and the inclined surface SU are opposed to and in contact with each other is set to the normal position of the first head holder 27 and the meshing state of the cam is set to the “normal state”, the first carriage 5 is Not stable. This is because, in the manufacturing process, it is difficult to accurately manufacture the cam convex portion 24eM of the slide cam 24 and the cam convex portion 27eM on the side of the first head holder 27 facing the cam convex portion 24eM, which causes a deviation. . Accordingly, a convex positioning member 60 is provided in the bottom region 5 b of the first carriage 5, and the position where the positioning portion 60 and the bottom surface of the first head holder 27 abut is the “normal position” of the first head holder 27. In this case, the meshing state of the cam is preferably set to the “normal state”.

  This “normal state” also has an effect that an error caused by stacking parts with respect to the gap L between the first recording heads 71 and 72 and the printing surface of the recording medium 150 can be made smaller than when the first head holder 27 is raised. Have. The second carriage 6 is also preferably provided with a positioning portion for the same reason. 11A, 14A, and the like, a distance D is provided between the cam convex portion 27d and the slide cam 24 in a state where the cam convex portions 27d and the slide cam 24 are separated from each other. This is because the first head holder 27 is positioned by the positioning unit 60. The positioning unit 60 is preferably provided for the first head holder 27 for the first carriage 5 and the corresponding head holder for the second carriage 6.

(2): As shown in FIGS. 10 and 11B, the cam convex portion 27eM formed on the lower surface of the cam convex portion 27d and the cam convex portion 24eM formed on the slide cam 24 face each other. This is a case of meshing. By moving the slide cam 24 to the right in the sub-scanning direction Y1-Y1 from the above-mentioned “normal state”, the inclined surface SU and the inclined surface SD come into contact with and slide, and the inclined surface SU is integrated with the inclined surface SU. The first head holder 27 is lifted, and the slide cam 24 is stopped at a position where the cam convex portion 27eM and the cam convex portion 24eM face each other.

  In this example, the first head holder 27 (the first recording heads 71 and 72) is raised from the “normal state” and separated from the recording medium reference plane OO, and the convex portion 24eM having a flat top portion and the top portion are formed. Since the flat convex portion 27eM faces and abuts, even if the slide cam 24 is slightly moved, the height positions of the first recording heads 71 and 72 are not affected. The state of this example is applied when the recording medium 150 sent along the recording medium reference plane OO is cardboard, and the gap L between the first nozzle surfaces 71a and 72a and the recording medium 150 is fixed. Value.

  The first head holder 27 (first recording heads 71 and 72) can be returned to the “normal state” by reversely driving the drive source 20 from the state of the present example in which the first head holder 27 is at the highest position. . Thus, by moving the two slide cams 24 by the same distance parallel to the sub-scanning direction by the pinions 23R and 23LP, the first head holder 27 can be moved up and down while being kept horizontal. The movement direction of the two slide cams 24 can switch the rotation direction of the drive source 20 and can move the first head holder 27 up and down.

  As described in the above (1) and (2), even if the first carriage 5 vibrates, the first head holder 27 moves by urging the first head holder 27 downward by the spring 31. There is an advantage that it does not vibrate. Whether the first head holder 27 and the second head holder that are lifted and lowered in this way are at a position suitable for a thick paper recording medium or a position suitable for a thin paper recording medium, etc. It is detected by a lift sensor 25 provided on each second carriage 6.

  In the above, as shown in FIGS. 2 to 5, 10, 11, etc., the first recording head lifting / lowering means 500 </ b> R (first recording head lifting / lowering means 500 </ b> L) holds the first recording heads 71 and 72 and lifts / lowers. The first head holder 27 that is supported in the first carriage 5 with the movement direction restricted only in the direction Z1-Z1, and the elastic means that urges the head holder convex portion 27d of the first head holder 27 in the up-and-down direction. As a spring 31 and the first head holder 27 urged by the elastic means, and supported by the first carriage 5 so as to be reciprocable in the sub-scanning direction Y1-Y1, and in the direction of the teeth at one end thereof. Includes a slide cam 24 having a rack 24RC formed in the main scanning direction X1-X1, and a pinion 23R · P (23L · P) meshing with the rack 24RC. The ON 23RP (23L · P) is configured coaxially with the first carriage right joint 23R as the first recording head lifting drive connecting means.

  The second recording head lifting / lowering means 600R (first recording head lifting / lowering means 600L) holds the second recording heads 73 to 75 and is supported in the second carriage 6 with the movement direction restricted only in the lifting / lowering direction Z1-Z1. The head holder (which is similar to the first head holder 27 and is not shown), a spring as elastic means for urging the head holder convex portion of the head holder in the ascending / descending direction, and the urging force applied by the elastic means A rack (supporting the rack 24RC) is supported by the second carriage 6 so as to reciprocate in the sub-scanning direction Y1-Y1 and has a toothing direction formed at one end thereof in the main scanning direction X1-X1. ) And a pinion 18R · P (18L · P) meshing with the rack, and the pinion 1 8R · P (18L · P) is configured coaxially with the drive transmission shaft 18J, the second carriage right joint 18R, and the second carriage left joint 18L as the second recording head lifting drive connecting means 18.

[Configuration example of connection means]
A specific example of connection means used to transmit power from the head lifting drive source 20 to the first recording head lifting drive connection means (first carriage right joint) 23R will be described. 15A and 15B, the drive source joint 19, the second carriage right joint 18R, the second carriage left joint 18L, the first carriage right joint 23R, the pinion 18L · P, 18P · P, 23R · P, etc. A perspective view is shown.

  FIG. 15A is a specific example applied to the second carriage right joint 18R and the pinion 18R / P that is coaxially integrated with the second carriage right joint 18R, and the first carriage right joint 23R and the first carriage This is a specific example that is applied to the pinion 23R · P that is coaxially integrated with the carriage right joint 23R.

  FIG. 15B shows a specific example applied to the drive source joint 19, and also applies to the second carriage left joint 18L and the pinion 18L / P coaxially integrated with the second carriage left joint 18L. It is an example.

  As shown in FIG. 15A, on the circular end surface 23a of the second carriage right joint 18R (first carriage right joint 23R), adjacent to the four convex portions 23b in the rotational direction of the joint 18R (23R). A concave portion 23c is formed between the convex portions 23b. Further, as shown in FIG. 15B, four convex portions 22b are adjacent to the circular end surface 22a of the drive source joint 19 (second carriage left joint 18L) in the rotational direction of the joint 19 (18L). A recess 22c is formed between the protrusions 22b.

  When the joint is connected by moving one joint in a direction approaching on the same axis with respect to the other joint, the four convex portions 23b are fitted into the four concave portions 22c, respectively, and the four convex portions 22b are respectively The four recessed portions 23c are fitted. Therefore, by this fitting, the drive source joint 19 (second carriage left joint 18L and pinion 18L · P), second carriage right joint 18R and pinion 18R · P (first carriage right joint 23R and pinion 23R · P) are made. It is rotated integrally.

  In the example of FIG. 15B, the pinion is formed as the pinion 18L / P only when the joint is the second carriage left joint 18L, and when the joint is the drive source joint 19, the rack is a direct drive target. Therefore, no pinion is formed at the drive source joint 19 part. The shape of each joint shown in FIG. 15 is not limited to the shape example illustrated in FIG. 15 as long as it has a function of transmitting the driving force of one joint to be connected to the other joint.

[Joint storage and connection means]
When the heights of the first recording heads 71 and 72 are adjusted according to the thickness of the recording medium 150, the heads are used to rotate the pinions 23RP and 23LP to drive the first recording head lifting and lowering means 500R and 500L. The power from the elevating drive source 20 must be guided to the first carriage right joint 23R. For that purpose, as shown in FIG. 3 or FIG. 4, the second carriage 6 is moved to the home position in advance to connect the drive source joint 19 and the second carriage right joint 18R, and the maintenance mechanism 8 makes the second movement. It is necessary that the position of the carriage 6 is fixed.

  Here, after the color image formation, as already shown in FIG. 3, the first carriage 5 is integrally connected to the second carriage 6 by the connecting member 49, and the second carriage left joint 18L and the first carriage right joint 23R are connected. Is connected, driving the head lifting drive source 20 leads the power to the first carriage right joint 23R, so that the head lifting drive source 20 can be lifted by driving the pinions 23RP and 23LP. is there.

  However, for example, after the monochrome image is formed and the second carriage 6 is at the home position but the first carriage 5 is not at the home position as shown in FIG. 4, the first carriage 5 is moved to the left. Before moving and contacting the second carriage 6, the first carriage right joint 23R is moved to the left side in the main scanning direction X1-X1 in the first carriage 5 in advance. Must be retracted to the storage position where it does not mesh with the second carriage right joint 18R.

  Then, the first carriage 5 is brought into contact with the second carriage 6, and then the connecting member 49 is operated in advance so that the connecting operation between the joints does not affect the positional accuracy of the recording head. 5 and the second carriage 6 are integrally connected, and then the first carriage right joint 23R is moved to the left in the main scanning direction X1-X1 so that the first carriage right joint 23R becomes the second carriage right joint 18R. The joint is moved to a connection position that meshes with each other to obtain a connection state between these joints.

  Further, when the first carriage 5 is separated from the second carriage 6 integrally connected by the connecting member 49 as in the case of forming a monochrome image after forming the color image, the first carriage 5 is previously set in the first carriage 5. Then, the first carriage right joint 23R is moved to the left in the main scanning direction X1-X1 and retracted to the storage position where the first carriage right joint 23R does not mesh with the second carriage right joint 18R. The connection is released and the first carriage 5 is separated.

  As described above, in the first carriage 5 having the first recording head elevating means 500R and 500L but not having the drive source, the first carriage 5 and the second carriage 6 are integrated when the joint is connected or disconnected. In this example, joint storage / connection means is provided and the first carriage right joint 23R is moved in the main scanning direction Y1-Y1 in order not to lower the coupling position accuracy of both carriages by performing the connection. The storage state and connection state are obtained.

  The configuration and operation of the joint housing / connecting means will be described with reference to FIGS. 16 is a perspective view of the storing / connecting means 41, FIG. 17 is a perspective view showing the storing / connecting means 41 together with a connecting member driving mechanism 181 as a connecting / releasing means, and FIG. 18 to FIG. The front view of the connection means 41 and the connection member drive mechanism 181, (b) shows the joint connection process in the storage / connection means 41.

  As shown in FIG. 16, the storage / connection means 41 is a support shaft (drive transmission) that holds the pinions 23L / P, 23R / P and the first recording head lifting drive connection means (first carriage right joint 23R) coaxially. Shaft 26), a support means (support 81) that supports the first carriage 5 so as to be movable and rotatable in the main scanning direction in accordance with the main scanning direction X1-X1. The storage guide 81b as a cam follower, which is a part of the means and attached to the support shaft via the support means, the pinion, the first recording head lifting drive connection means, the support shaft, and the storage guide are the second recording. The urging means (coil spring 86) that urges the head ascending / descending drive connecting means 18 to move toward the head and the urging means (coil bar) are brought into contact with the storage guide. 86) prevents the movement of the support shaft and prevents the first recording head elevating drive connecting means (first carriage right joint 23R) from receiving the power from the head elevating drive source 20 in accordance with the rotation, and the retracted state in which the power from the head elevating drive source 20 is not transmitted. A storage cam 87 for switching to the joint retracted state, a storage cam drive source (motor 47) for rotating the storage cam 87, and a gear train are provided.

  In the vicinity of the step portion 5a in the first carriage 5, two support plates 80 are arranged upright on the bottom region 5b at an interval so as to face each other in the main scanning direction X1-X1. The drive transmission shaft 26 is inserted into the circular holes 80h formed in the support plates 80, and the pinion 23R / the one of the drive transmission shafts 26 protruding outward from the support plate 80 on the second carriage 6 side is provided. A first carriage right joint 23R integrated with P is fixed. Pinions 23L and P are fixed to the other end portion of the drive transmission shaft 26 protruding outward from the opposite support plate 80.

  In the drive transmission shaft 26, a support body 81 made of a housing is inserted at a substantially intermediate position between the two support plates 80. An E-ring groove 82 is formed in a substantially central portion of the drive transmission shaft 26 located inside the support 81, and an E-ring 83 is attached to the groove 82. A positioning collar 84 is slidably fitted to the drive transmission shaft 26 inside the support 81 and closer to the pinion 23RP than the E-ring 83. One end of the positioning collar 84 is in contact with the E-ring 83, and the other end is press-fitted and fixed in an insertion hole 81h1 of the drive transmission shaft 26 formed in the support 81.

  A positioning collar 85 is also fitted to the drive transmission shaft 26 inside the support body 81 and closer to the pinion 23LP than the E ring 83. One end side of the positioning collar 85 is in contact with the E ring 83, and the other end side is supported. It is press-fitted and fixed in an insertion hole 81 h 2 of the drive transmission shaft 26 formed in the body 81. Thus, the drive transmission shaft 26 is integrated with the support body 81.

  In a state where the support body 81 is positioned approximately in the middle of the two support plates 80, the support body 81 can reciprocate in the main scanning direction X1-X1 together with the drive transmission shaft 26, and the stroke is the first carriage right joint. 23R is large enough to connect to the second carriage left joint 18L and to release the connection to the storage state.

  An extensible coil spring 86 is provided between the wall 81a of the support 81 to which the positioning collar 85 is fixed (or the end of the positioning collar 85) and the support plate 80 so as to wind the drive transmission shaft 26. Thus, the drive transmission shaft 26, the support 81, the pinions 23L and P and the pinion 23RP, and the first carriage right joint 23R are urged to move in the main scanning direction X1-X1 to the second carriage 6 side. ing.

  The movement of the drive transmission shaft 26 and the integrated object due to the urging force is prevented when the cam surface of the storage cam 87 which is a disc-shaped cam contacts the storage guide plate 81b provided integrally with the support 81. ing. The pinion 23L · P and the pinion 23R · P mesh with the corresponding rack 24RC.

  The direction of the rotation axis of the storage cam 87 is the main scanning direction X1-X1, and the cam surface has a convex part with a large distance from the rotational axis and a circular cam with a concave part with a small distance from the rotational axis, By rotationally driving the storage cam 87, the pinions 23L and P and the pinions 23R and P are maintained in the main scanning direction X1-X1, which is the direction of the teeth of the rack 24RC, while maintaining the meshed state with the corresponding rack 24RC. The first carriage right joint 23R can be moved and connected to the second carriage left joint 18L, or the connection can be released and stored.

  The rack 24RC has a larger width in the main scanning direction X1-X1 than the pinion 23RP, and meshes with the rack 24RC even if the pinions 23R · P and 23L · P move. Further, even if the pinions 23R · P and 23L · P are moved in the main scanning direction X1-X1, the rack 24RC does not move because the directions of both teeth are parallel to the main scanning direction X1-X1.

  For example, in FIG. 20A, the cam surface of the convex portion of the storage cam 87 is in contact with the storage guide plate 81b, and the first carriage right joint 23R and the second carriage left joint 18L are separated from each other. Yes. From this state, the rotation of the storage cam 87 advances, and when the cam surface of the recess of the storage cam 87 contacts the storage guide plate 81b as shown in FIG. 21A, the storage guide plate 81b is closer to the second carriage 6. Therefore, the first carriage right joint 23R and the second carriage left joint 18L are engaged with each other. If the storage cam 87 is reversed from this state, it can be restored to the state shown in FIG.

[Connection / release of both carriages by connection / release means]
As shown in FIG. 3, in this example, a connecting member 49 is used as a means for connecting the first carriage 5 and the second carriage 6 integrally at their home positions or for releasing the connection. A U-shaped member is used as the connecting member 49, and both the first carriage 5 and the second carriage 6 are partially sandwiched between the first carriage 5 and the second carriage 6 (each side plate in this example). Connect the carriages together. When releasing the connection between the two carriages, the connecting member 49 is pulled out from the state where the two side plate portions are sandwiched. As described above, the connecting / releasing operation by the connecting member 49 can be performed by a reciprocating operation.

  The connection / release means (connection drive mechanism 181) is a position where the first carriage 5 and the second carriage 6 are integrally connected by a reciprocating operation (FIG. 21) and a position where the integral connection is released (FIG. 21). 19), and a connecting member driving mechanism for displacing the connecting member 49. The connecting member driving mechanism includes guide means (guide rod 90) for restricting the reciprocating direction of the connecting member 49. ), A rack 49RC formed on the connecting member 49, a pinion 48 that meshes with the rack and reciprocates the connecting member by rotation thereof, and a gear drive source (motor 47) that rotates the pinion. This gear drive source is the same as the storage cam drive source that drives the storage / connection means.

  The configuration and operation for connecting and releasing the first carriage 5 and the second carriage 6 by the connecting member 49 will be described with reference to FIGS. The connecting member 49 is a U-shaped member, and the opening side is directed downward in the vertical direction Z1-Z1, and the movement direction is restricted in the vertical direction Z1-Z1 so as to allow reciprocation. A connecting member 49 is slidably fitted to the two guide rods 90 as guide means in the vertical direction Z1-Z1. The lower end of the guide bar 90 is fixed to the carriage 5.

  As described above, the side plate of each carriage is sandwiched between the connecting members 49. However, in order to increase the accuracy of sandwiching, the thickness accuracy is increased and the surface is smoothed. The first carriage 5 is a connecting member receiving portion 183, and the second carriage 6 is a connecting member receiving portion 182. The gap d (refer to FIG. 18) of the opposing member that constitutes the pinch that sandwiches the connecting member receiving portions 182 and 183 in the connecting member 49 is large enough to slide and fit with the connecting member receiving portions 182 and 183 overlapped. That ’s right.

  A rack 49RC is formed on the back surface of the connecting member 49 in the belt-shaped region extending in the vertical direction Z1-Z1 in the vertical direction Z1-Z1. The rack 49RC is engaged with a pinion 48 whose rotation axis is in the main scanning direction X1-X1, and when the pinion 48 is rotated forward and backward, the connecting member 49 is moved up and down to be in a connected state and a released state. Can be switched.

  Since the rotation shafts of the pinion 48 and the storage cam 87 are both in the main scanning direction X1-X1, the intermediate gear 45 is interposed coaxially with the shaft of the pinion 48, and the intermediate gear 45 is driven to drive both the connecting members 49. The connection / release of the carriage can be interlocked with the storage / connection of the joint by the storage cam 87.

  Therefore, by engaging the worm gear 46 with the intermediate gear 45 and further engaging the worm 52 directly connected to the motor 47 with the worm gear 46, the motor 47 as a common drive source is used to connect / release the two carriages by the connecting / release means. And storage / connection of the joint by the storage / connection means can be interlocked.

The above interlocking operation will be exemplified.
(A): In the state shown in FIG. 18, the first carriage 5 is approaching the second carriage 6 from a separated position with respect to the second carriage 6 in the home position, and the open side of the connecting member 49 The protruding portion of the storage cam 87 is in contact with the storage guide plate 81b, and the first carriage right joint 23R is stored (retracted) to the left.

(B): As shown in FIG. 19A, the first carriage 5 reaches the hoe position, and the two connecting member receiving portions 182 and 183 are overlapped. When the motor 47 is driven and each gear rotates in the direction indicated by the arrow, the connecting member 49 starts to descend, but has not yet reached the position where the connecting member receiving portion 182 is captured. As shown in an enlarged view in FIG. 19B, the first carriage right joint 23R is spaced apart from the second carriage left joint 18L with a gap Δ.

(C): As shown in FIG. 20A, the connecting member 49 slightly sandwiches the two connecting member receiving portions 182 and 183, but at this stage, the first carriage ridge 5 and the second carriage 6 are not yet connected. It has not been integrated. Therefore, the storage cam 87 still abuts the convex portion on the storage guide plate 81b. As shown in an enlarged view in FIG. 20B, the first carriage right joint 23R is still separated from the second carriage left joint 18L with a gap Δ. However, the convex portion of the storage cam 87 is in a state where the substantially end portion thereof is in contact with the storage guide plate 81b, and the time when the first carriage right joint 23R starts the left line is approaching.

(D): As shown in FIG. 21 (a), the connecting member 49 is lowered to a position where the two connecting member receiving portions 182 and 183 are integrally connected, and the storage cam 87 has a recess in the storage guide plate 81b. As shown in an enlarged view in FIG. 21B, the first carriage right joint 23R is in a state of being connected to the second carriage left joint 18L.

  Thus, in this example, the first recording head lifting drive connecting means (first carriage right joint) 23R by the storage / connecting means 41 and the other end of the second recording head lifting drive connecting means 18 (second carriage left joint). 18L) is performed after the first carriage 5 and the second carriage 6 are coupled by the coupling / release means (coupling member 49). The head lift drive is connected after the carriage is connected. Further, the storing (retracting) operation of the first carriage right joint 18R from the second carriage left joint 18L by the storing / connecting means 41 is performed in the order of reversely going through the steps (a) to (d). The storage (retraction) operation of the (one carriage right joint) 23R is performed in a state where the first carriage 5 and the second carriage 6 are connected, and after the storage (retraction) operation, the first carriage 5 and the second carriage 6 is released. As described above, the carriage is separated after the head lifting drive joint is separated, so that the position of the second carriage is not affected by the separation of the lifting drive joint.

  After the first carriage 5 and the second carriage 6 are connected by the connecting / releasing means, the first recording head lifting drive connecting means 23R by the storing / connecting means 41 and the other end 18L of the second recording head lifting drive connecting means are connected. The rotational position of the storage cam 87 that contacts the storage guide 81b and the reciprocating direction of the rack formed in the connecting member 49 (vertical direction Z1-Z1) of the pinion 48 so that the connection operation is performed. A relationship with the meshing position is determined.

  Even when such a motor or cam mechanism is not used for the operation of the storing / connecting means 41 and the connecting / releasing means for both carriages, as shown in this example, the lifting drive is connected after the carriage is connected, and the carriage is lifted before the carriage is separated. It is desirable to perform drive separation. The former does not affect the head position after the connection when the carriage is connected first and the head position is accurately obtained and the connection of the lift drive is performed. The latter is because it is difficult to affect the position of the second carriage 6 held by the maintenance mechanism 8 by connecting the lift drive before carriage separation.

  In addition, by providing the first drive transmission means storage mechanism in the first carriage 5 as described above, even if the carriages are separated, it is not necessary to provide a drive source in each carriage, so that the machine width is not increased.

In the above description, the Z1-Z1 direction is exemplified as the vertical direction for convenience of explanation, but it is not necessary to limit the Z1-Z1 direction to the vertical direction in the implementation of the present invention, and X1-X1, Y1-Y1, Z1-Z1 The invention can be implemented by the direction indicated by the three-dimensional orthogonal coordinates shown.

1 Guide rod 2 Sub guide 3 Left side plate 4 Right side plate 5 First carriage (monochrome carriage)
5a Step 5b Bottom region 5c Carriage hole 5d Side wall 6 Second carriage (color carriage)
8 Maintenance mechanism 9 Main scanning motor 10 Timing belt 11 Encoder sheet 13 Tensioner 14 Bearing portion 15 Belt holding portion 16, 16 'Guide portion 17 First encoder sensor 18 Second recording head lifting drive connecting means 18J Drive transmission shaft 18R Second carriage Right joint 18L Second carriage left joint 18R / P, 18L / P, 23R / P, 23L / P Pinion 19 Drive source side drive connection means (drive source joint)
20 Head lift drive source 22a Circular end face 23R First recording head lift drive connection means (first carriage right joint)
23L First carriage pinion 23a Circular end surface 24 Slide cam 24RC, 49RC Rack 25 Elevation sensor 18, 26 Drive transmission shaft 27 First head holder 27b Holder hole 27c Side wall 27d Head holder convex portion 27e Holder cam surfaces 22b, 23b, 24eM, 27eM Convex Portions 23c, 24eV, 27eV Recess 31 Spring 41 Storage / connection means 45 Intermediate gear 47 Motor 48 Pinion 49 Connecting member 50 Spring pressing portion 52 Worm 60 Positioning member 71, 72 First recording head 71a, 72a First nozzle surface 71A, 71B Rectangular convex portions 73, 74, 75 Second recording head 80 Support plate 80h Circular hole 81 Support body 81a Wall portion 81b Storage guide 81h1, 81h2 Insertion hole 82 Groove 83E Ring 84, 85 Positioning collar 86 Coil spring 87 Storage cam 90 Draft Rod 100 recording apparatus 121 drive pulley 122 driven pulley 150 recording medium 160 support 181 coupling member driving mechanism (coupling and releasing means)
182 and 183 Connecting member receiving portions 500R and 500L First recording head elevating means 600R and 600L Second recording head elevating means d Gap D Distance L Gap OO Recording medium reference surface SD, SU Inclined X1-X2 Main scanning direction Y1- Y1 Sub-scanning direction Z1-Z1 vertical direction (lifting direction)
Δ Clearance

See Japanese Patent Application Laid-Open No. 2007-223232 See JP-A-2005-271531 See Japanese Patent No. 2785031 Refer to Japanese Patent No. 3982519 See JP2003-162137A

Claims (10)

A first recording head, and a first carriage having first recording head raising / lowering means for raising and lowering the first recording head and movable in the main scanning direction;
A second recording head, and a second carriage having second recording head lifting / lowering means for moving the second recording head up and down and movable in the main scanning direction;
A head lifting drive source for driving the first recording head lifting means and the second recording head lifting means;
Drive source side connection means provided integrally with the head lifting drive source;
Second recording head lifting drive connection means for the second carriage, one end of which is connected to the driving source side connection means and transmits a driving force to the second recording head lifting means;
First recording head lifting drive connecting means for a first carriage connected to the other end of the second recording head lifting drive connecting means and transmitting a driving force to the first recording head lifting means;
A connection / release means for connecting the first carriage and the second carriage and releasing the connection;
An image forming apparatus having
A first recording head lifting drive connecting means of the first carriage is connected to the other end of the second recording head lifting drive connecting means of the second carriage so that a drive for raising and lowering the head is transmitted; It has storage and connection means that can be in a storage state that is disconnected,
The storing / connecting operation of the first recording head raising / lowering drive connecting means of the first carriage by the storing / connecting means is interlocked with the connecting / release operation of the first carriage and the second carriage by the connecting / release means. An image forming apparatus. The image forming apparatus according to claim 1.
The connecting operation of the first recording head lifting drive connecting means and the other end of the second recording head lifting drive connecting means by the storing / connecting means is performed by the connecting / releasing means between the first carriage and the second carriage. An image forming apparatus which is performed after the connection. The image forming apparatus according to claim 1 or 2,
The first and second recording head lifting / lowering means are not moved by the connecting operation of each driving connection means for driving force input and the operation of entering the storage state in which the connection is released with respect to each head lifting / lowering driving connection means. An image forming apparatus. The image forming apparatus according to any one of claims 1 to 3,
The first carriage can be driven back and forth in the main scanning direction, the head lifting drive source is fixed on one end side in the main scanning direction, and the second carriage and the first carriage of the first carriage from the side closer to the head lifting drive source. The second carriage is arranged in order, and the second carriage is integrally connected to the first carriage by the connecting / releasing means, so that the second carriage is movable in the main scanning direction together with the first carriage. Forming equipment. 5. The image forming apparatus according to claim 4, wherein a position where the second recording head lifting drive connecting means integrated with the second carriage is close to the head lifting drive source to a position where it is connected to the driving source side connecting means. The home position of the second carriage,
A position where the first carriage is close to a position where it can be connected by the connecting / releasing means with respect to the second carriage positioned at the home position is defined as a home position of the first carriage.
With the first carriage and the second carriage in their respective home positions, the storage / connection operation of the head lifting drive connection means of the first carriage by the storage / connection means and the connection / release means by the connection / release means. An image forming apparatus characterized in that connection and release operations of one carriage and the second carriage are possible. The image forming apparatus according to any one of claims 1 to 5,
The first recording head lifting / lowering means holds the first recording head and is restricted in the moving direction only in the lifting / lowering direction and supported in the first carriage;
Elastic means for urging the head holder in the up and down direction;
A slide having a rack that supports the head holder biased by the elastic means and is supported by the first carriage so as to be reciprocally movable in the sub-scanning direction, and has a streak direction formed at one end thereof in the main scanning direction. With cam,
A pinion meshing with the rack;
Have
An image forming apparatus, wherein the pinion is configured coaxially with the first recording head lifting drive connecting means. The image forming apparatus according to any one of claims 1 to 6,
The second recording head lifting / lowering means holds the second recording head and is restricted in the moving direction only in the lifting / lowering direction and supported in the second carriage,
Elastic means for urging the head holder in the up and down direction;
A slide having a rack that supports the head holder biased by the elastic means and is supported by the second carriage so as to be reciprocally movable in the sub-scanning direction, and has a toothed direction formed at one end thereof in the main scanning direction. With cam,
A pinion meshing with the rack;
Have
The image forming apparatus, wherein the pinion is configured coaxially with the second recording head lifting drive connecting means. The image forming apparatus according to any one of claims 1 to 7,
The storing / connecting means includes:
A support shaft that coaxially holds the pinion and the first recording head lifting drive connection means;
A support means for supporting the first carriage by the first carriage so that the axis of the support shaft is aligned with the main scanning direction, and is movable and rotatable in the main scanning direction;
A storage guide as a cam follower attached to the support shaft;
Biasing means for biasing the pinion, the first recording head lifting drive connecting means, the support shaft, and the storage guide so as to move in a direction approaching the second recording head lifting drive connecting means;
A storage cam that contacts the storage guide to prevent the biasing means from moving the support shaft and to switch the first recording head lifting drive connection means between a connected state and a stored state according to rotation;
An image forming apparatus comprising: a storage cam drive source for rotating the storage cam. The image forming apparatus according to any one of claims 1 to 8,
The connecting / releasing means is
A connecting member that is displaced to a position where the first carriage and the second carriage are integrally connected by a reciprocating operation and a position where the integrated connection is released, and a connecting member drive that displaces the connecting member. Consisting of mechanism,
The connecting member drive mechanism
Guiding means for regulating the direction of reciprocation of the connecting member;
A rack formed on the connecting member;
A pinion that meshes with the rack and reciprocates the connecting member by rotation thereof;
A gear drive source for rotating the pinion,
This gear drive source is common with a storage cam drive source for driving the storage / connection means. The image forming apparatus according to claim 9.
After the connection between the first carriage and the second carriage by the connecting / releasing means, the first recording head lifting drive connecting means by the storing / connecting means and the other end of the second recording head lifting drive connecting means; The relationship between the contact position in the rotational direction of the storage cam that contacts the storage guide and the meshing position of the pinion in the reciprocating direction of the rack formed on the coupling member An image forming apparatus characterized by the above.

Images