Abstract:
An image forming device includes a plurality of medium feed units configured to feed a recording medium on respective carrying routes, an image forming unit configured to form an image on the recording medium fed from one of the plurality of medium feed units, a first roller provided on a common route of the carrying routes, the first roller being configured to rotate at a first circumferential velocity and carry, to the image forming unit, the recording medium fed from one of the plurality of medium feed units, and a control unit configured to control the first circumferential velocity of the first roller depending on from which of the plurality of medium feed units the recording medium is fed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119 from Japanese Patent Application No. 2007-304054 filed on Nov. 26, 2007. The entire subject matter of the application is incorporated herein by reference. 
     BACKGROUND 
     1. Technical Field 
     The following description relates to one or more image forming devices. 
     2. Related Art 
       FIG. 5  is a side view schematically showing an entire configuration of a known image forming device with a manual sheet feed device incorporated therein. In the image forming device, a right side in  FIG. 5  corresponds to a front face (operation face), on which handles  51  of sheet feed cassettes  12  and  12   a  and a manual sheet feed slot  40  are provided. 
     A sheet  14  of a normal size fed from the sheet feed cassette  12  or  12   a  by a sheet feed roller  13  is carried by a carrying roller  11 , through timing adjustment by a pair of registration rollers  15 , toward a transfer portion under a belt photoconductive body  16 . A toner image is formed on the photoconductive body with an electrification charger  17 , a laser scanning optical system, and a developing unit that are provided around the photoconductive body  16  in an order of a turning direction indicated by an arrow. The toner image formed is transferred onto the sheet  14  due to operation of a transfer charger  20 . The toner image transferred on the sheet  14  is fixed by a fixing unit  21 . Then, the sheet  14  with the toner image fixed thereon is discharged with a pair of sheet discharge rollers  23  and a switching claw  24  of a sheet discharge unit  22 , via sheet discharge guides  25  and  26  and a pair of sheet discharge rollers  27  and  28 , from a sheet discharge slot  29  to a stack portion  30  provided on an upper unit with an image-formed surface down, or from a rear sheet discharge slot  31  to a catch tray T with the image-formed surface up. 
     Further, a sheet loading tray  32  is provided in the vicinity of the manual sheet feed slot  40 , and a sheet placed in the sheet loading tray  32  is carried with the carrying roller  11  (for example, see Japanese Patent Provisional Publication No. HE15-238607). In general, rollers provided in a sheet carrying route are adopted such that a roller provided on a further downstream side in a carrying direction carries a sheet at a lower carrying speed. For example, in the aforementioned known image forming device, when a sheet is conveyed from the sheet feed cassette  12  or  12   a , each roller is adopted such that a circumferential velocity thereof is higher in an order of the sheet feed roller  13 , the carrying roller  11 , and the pair of registration rollers  15 . 
     This is because a production tolerance is required for manufacturing of each sort of rollers since it is hard to form each sort of rollers in the same shape. 
     For instance, even though the sheet feed roller  13 , the carrying roller  11 , and the pair of registration rollers  15  are all designed to rotate at an identical circumferential velocity, the carrying speed for the sheet is not constant due to the production tolerance of each roller. Therefore, a sheet might be carried in a strained state. When a sheet is conveyed in a strained state, a member employed in the carrying route might be damaged and shifted from an appropriate position thereof. To avoid such undesired situations, in general, each roller is adopted such that a roller provided on a further downstream side in the carrying direction carries a sheet at a lower carrying speed. Thereby, a sheet is conveyed in a manner bent between any couple of adjacent rollers in the carrying direction. 
     SUMMARY 
     In the aforementioned known image forming device, a sheet fed from the sheet feed cassette  12  or  12   a  is conveyed by the sheet feed roller  13  which rotates at a high circumferential velocity. Hence, a speed difference is caused between carrying speeds for a sheet fed from the sheet feed cassette  12  or  12   a  and a sheet fed manually. 
     Specifically, the sheet fed from the sheet feed cassette  12  or  12   a  is always pushed toward an upstream side at a high speed by the sheet feed roller  13 . Therefore, the carrying roller  11  and/or the pair of registration rollers  15  might slip with respect to the sheet. Thus, the sheet fed from the sheet feed cassette  12  or  12   a  is conveyed at a higher speed than a carrying speed in design to be attained by the carrying roller  11  or the pair of registration rollers  15 . 
     Meanwhile, the sheet fed manually is conveyed by the carrying roller  11  which is rotated in response to a sheet being placed on the sheet loading tray  32 . Hence, the sheet is conveyed at a carrying speed in design to be attained by the carrying roller  11 . Thereby, there might be a problem that an image transferred position on the sheet fed from the sheet feed cassette  12  or  12   a  and that on the sheet fed manually are different from each other. 
     Aspects of the present invention are advantageous to provide one or more improved image forming devices that make it possible to always form a consistently-positioned image on a sheet regardless of whether the sheet is fed manually or from a sheet feed cassette. 
     According to aspects of the present invention, an image forming device is provided, which includes a plurality of medium feed units configured to feed a recording medium on respective carrying routes, an image forming unit configured to form an image on the recording medium fed from one of the plurality of medium feed units, a first roller provided on a common route of the carrying routes, the first roller being configured to rotate at a first circumferential velocity and carry, to the image forming unit, the recording medium fed from one of the plurality of medium feed units, and a control unit configured to control the first circumferential velocity of the first roller depending on from which of the plurality of medium feed units the recording medium is fed. 
     Further, the control unit may control the first circumferential velocity of the first roller such that the recording medium is carried to the image forming unit at substantially the same carrying speed regardless of the carrying routes. 
     In some aspects of the present invention, the first circumferential velocity of the first roller, which is provided on the common route of the carrying routes, is controlled depending on from which of the plurality of medium feed units the recording medium is fed. Thereby, it is possible to carry the recording medium to the image forming unit at substantially the same carrying speed and thus form a consistently-positioned image on the recording medium, regardless of the carrying routes. 
    
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         FIG. 1  is a cross-sectional side view schematically showing an entire configuration of an LED printer when an upper case is closed in an embodiment according to one or more aspects of the present invention. 
         FIG. 2  is an enlarged view schematically showing a part of the LED printer shown in  FIG. 1  in the embodiment according to one or more aspects of the present invention. 
         FIG. 3  is a block diagram schematically showing an electrical configuration of the LED printer in the embodiment according to one or more aspects of the present invention. 
         FIG. 4  is a flowchart showing operations to be executed by the LED printer in the embodiment according to one or more aspects of the present invention. 
         FIG. 5  is a cross-sectional side view schematically showing a known image forming device. 
     
    
    
     DETAILED DESCRIPTION 
     It is noted that various connections are set forth between elements in the following description. It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. Aspects of the invention may be implemented in computer software as programs storable on computer-readable media including but not limited to RAMs, ROMs, flash memory, EEPROMs, CD-media, DVD-media, temporary storage, hard disk drives, floppy drives, permanent storage, and the like. 
     Hereinafter, an embodiment according to aspects of the present invention will be described with reference to the accompanying drawings.  FIG. 1  is a cross-sectional side view schematically showing an entire configuration of an LED printer  5  in an embodiment according to aspects of the present invention. In the LED printer  5  shown in  FIG. 1 , a left side, a right side, a back side, and a front side on the figure are defined as a front side, a rear side, a left side, and a right side, respectively. 
     1. General Overview of LED Printer 
     In  FIG. 1 , an upper case  1  is supported, rotatably with respect to a mechanical unit  3 , by a rotational shaft hole  2  provided at a rear side of the upper case  1  and a rotational shaft  4  provided at a rear side of the mechanical unit  3 . Further, the mechanical unit  3  has an opening  3   a  at an upper side thereof. It is noted that  FIG. 1  shows a state where the upper case  1  is closed with respect to the mechanical unit  3 . 
     As shown in  FIG. 1 , in the mechanical unit  3  of the LED printer  5 , an image forming unit  60  configured to form an image on a recording sheet such as a paper and an OHP transparent sheet and a feeder unit  70  configured to feed a sheet to the image forming unit  60  are incorporated. 
     Meanwhile, the upper case  1  is provided with a catch tray  45  configured to be loaded with a sheet, on which image formation has been completed, discharged from a discharge slot  8 . 
     Further, the image forming unit  60  is attached to a frame that constitutes a device main body. The frame includes substantially plate-shaped side frames (not shown) provided at both ends in a right-to-left direction of the mechanical unit  3 , a bottom plate (not shown) extending in the right-to-left direction so as to connect respective lower ends the side frames, and a top plate (not shown) connecting respective upper ends of the side frames. 
     2. Image Forming Unit 
     The image forming unit  60  includes four drum units  61 K,  61 Y,  61 M, and  61 C detachably disposed that respectively correspond to black (K), yellow (Y), magenta (M), and cyan (C) in an order from an upstream side in an arrow A direction indicating a carrying direction of a sheet. 
     The drum units  61 K,  61 Y,  61 M, and  61 C are provided with photoconductive bodies  62 K,  62 Y,  62 M, and  62 C that rotate in an arrow B direction. Images of the predetermined colors are sequentially transferred onto a sheet, which is conveyed in the arrow A direction while being stuck to a carrying belt  68 , by the photoconductive bodies  62 K,  62 Y,  62 M, and  62 C and transfer rollers  63 K,  63 Y,  63 M, and  63 C rotated in concord with the photoconductive bodies  62 K,  62 Y,  62 M, and  62 C, respectively. Thereafter, the images of the predetermined colors on the sheet are thermally fixed with a fixing unit  56 . Then, the sheet is discharged by feed rollers  57  to a catch tray  45  provided to the upper case  1 . 
     Meanwhile, the upper case  1  includes four LED units  67 K,  67 Y,  67 M, and  67 C provided in positions that correspond to circumferential surfaces of the photoconductive bodies  62 K,  62 Y,  62 M, and  62 C of the drum units  61 K,  61 Y,  61 M, and  61 C, respectively. 
     LED heads  65 K,  65 Y,  65 M, and  65 C (described below) provided at respective distal ends of the LED units  67 K,  67 Y,  67 M, and  67 C are disposed close to the respective circumferential surfaces of the photoconductive bodies  62 K,  62 Y,  62 M, and  62 C. Thereby, it is possible to expose the circumferential surfaces of the photoconductive bodies  62 K,  62 Y,  62 M, and  62 C. Each of the photoconductive bodies  62 K,  62 Y,  62 M, and  62 C is rotated in the arrow B direction and exposed linearly along the right-to-left direction (i.e., main scanning direction) thereof. 
     It is noted that the drum units  61 , photoconductive bodies  62 , transfer rollers  63 , LED units  67 , and LED heads  65  in general and, unless specified otherwise, are configured in the same manner, respectively. If it is required to distinguish each element of the same sort of component from the other elements, each element will be distinguished with a reference character (K), (Y), (M), or (C) representing a corresponding color attached thereto. 
     3. Feeder Unit 
     As illustrated in  FIG. 1 , the feeder unit  70  includes a sheet feed cassette  71  detachably attached to a lowermost portion of the mechanical unit  3  and a pickup roller  72  provided at an upper front portion of the sheet feed cassette  71  so as to feed a sheet to the image forming unit  60 . Further, the feeder unit  70  includes a separation roller  73  configured to separate the sheet fed by the pickup roller  72  on a sheet-by-sheet basis while rotating and a separation pad  74 . 
     On a downstream side of the separation roller  73  and separation pad  74  in the carrying direction, a sheet feed roller  33  configured to feed a sheet while rotating is provided. Further, on a downstream side of the sheet feed roller  33  in the carrying direction, a sensor D 1  configured to detect whether a sheet passes therethrough is provided. In addition, the pair of registration rollers  35  provided on an inlet port side of the image forming unit  60  is configured to convey a sheet while rotating and perform a registration operation. Further, a sensor D 3  configured to detect whether a sheet passes therethrough is provided on a downstream side of the pair of registration rollers  35 . 
     4. Manual Sheet Feed Mechanism 
       FIG. 1  shows a state where a manual sheet feed tray  41  is closed. Meanwhile,  FIG. 2  is a cross-sectional side view schematically showing a relevant part when the manual sheet feed tray  41  is opened. The LED printer  5  includes a manual sheet feed mechanism  42  configured to convey a sheet fed manually from a front face side of the LED printer  5  to a transferring position. The manual sheet feed mechanism  42  is provided with the manual sheet feed tray  41  and an opening  43  through which a sheet is inserted. 
     The opening  43  is formed as a rectangular through hole at a front side of the mechanical unit  3 . The manual sheet feed tray  41  is provided to cover the opening  43 . Specifically, the sheet feed tray  41  is configured with a cover  41   a  as a front wall of the mechanical unit  3  and a tray portion  41   b  configured to be loaded with one or more sheets to be manually fed. As illustrated in  FIG. 2 , a lower portion of the cover  41   a  is supported rotatably around a cover rotational shaft  44  in an openable and closable manner with respect to the mechanical unit  3 . In addition, a sensor D 2  configured to detect whether there is a sheet on the tray portion  41   b  is provided on a downstream side of the manual sheet feed tray  41  in the carrying direction. 
     5. Electrical Configuration of LED Printer 
     Next, an electrical configuration of the LED printer  5  will be described.  FIG. 3  is a block diagram schematically showing an electrical configuration of the LED printer  5 . 
     The LED printer  5  is provided with a control device  80  that includes a CPU  81 , a ROM  82 , a RAM  83 , a control unit  85 , and a network interface  84 . Various control programs, various settings, and initial values for controlling the LED printer  5  are stored on the ROM  82 . The RAM  83  is employed as a work area into which the various control programs are loaded or a memory area that temporarily stores therein print data. 
     The CPU  81  controls each constituent element of the laser printer  1  via the control unit  85 , while causing the RAM  83  to store thereon processed results, in accordance with a control program read out from the ROM  82 . 
     The network interface  84 , which is connected with an external device such as a computer  86 , receives a print command or print data transmitted by the computer  86 . 
     The control unit  85  includes an ASIC, and is electrically linked with each constituent element of the LED printer  5  such as a main motor  90 , a sub motor  91 , the sensor D 1 , the sensor D 2 , the sensor D 3 , a solenoid  100  for the separation roller, a solenoid  101  for the sheet feed roller. 
     The main motor  90  is connected with the aforementioned separation roller  73  (pickup roller  72 ), sheet feed roller  33 , and photoconductive body  62  via a gear mechanism (not shown), and configured to drive and rotate the separation roller  73  (pickup roller  72 ), sheet feed roller  33 , and photoconductive body  62  in synchronization with each other. Further, the sub motor  91  is configured to drive and rotate the registration rollers  35 . 
     The solenoid  100  for the separation roller is provided as a clutch mechanism between the main motor  90  and the separation roller  73 . When the solenoid  100  for the separation roller is set ON, a driving force is transmitted from the main motor  90  to the separation roller  73 . Meanwhile, when the solenoid  100  for the separation roller is set OFF, the transmission of the driving force is blocked. Further, the separation roller  73  and the pickup roller  72  are linked via the gear mechanism such that respective circumferential velocities thereof are the same. Therefore, when the solenoid  100  for the separation roller is set ON, the driving force is transmitted from the main motor  90  to the pickup roller  72  as well. Meanwhile, when the solenoid  100  for the separation roller is set OFF, the transmission of the driving force is blocked. 
     Additionally, the solenoid  101  for the sheet feed roller is provided as a clutch mechanism between the main motor  90  and the sheet feed roller  33 . When the solenoid  101  for the sheet feed roller is set ON, the driving force is transmitted from the main motor  90  to the sheet feed roller  33 . Meanwhile, when the solenoid  101  for the sheet feed roller is set OFF, the transmission of the driving force is blocked. 
     6. Operation of Paper fed from Sheet Feed Cassette in Printing 
     A sheet fed from the sheet feed cassette  71  is detected by the sensor D 1  when a leading edge thereof passes through the pickup roller  72 , the separation roller  73 , and the sheet feed roller  33 . When the leading edge of the sheet is detected by the sensor D 1 , the transmission of the driving force to the separation roller  73  (and the pickup roller  72 ) is blocked by the solenoid  100  for the separation roller, and the separation roller  73  is rotated by the sheet being conveyed. Thereafter, the sheet is conveyed by rotation of the sheet feed roller  33  to a downstream side in the carrying direction. 
     Additionally, when the leading edge of the sheet being conveyed is detected by the sensor D 1 , the rotations of the registration rollers  35  are stopped with the leading edge of the sheet contacting the registration rollers  35  stopped. In the registration operation here, skew correction of the sheet is executed. Thereafter, the registration rollers  35  are driven again, and the leading edge of the sheet is carried to the image forming unit  60 . It is noted that, when the leading edge of the sheet passing through the registration rollers  35  is detected by the sensor D 3 , exposure operations by the LED units  67  are started. Thereafter, the sheet is conveyed by the carrying belt  68 , and four sorts of color images (black, yellow, magenta, and cyan) are sequentially formed. 
     7. Operation of Sheet Fed Manually in Printing 
     A sheet fed from the manual sheet feed tray  41  is pushed from the opening  43  by a user to a position where the sheet establishes contact with the registration rollers  35 , and placed on the tray portion  41   b  of the manual sheet feed tray  41 . Thereby, existence of the sheet is detected by the sensor D 2 . At this time, the registration rollers  35  is in a stopped state where the transmission of the driving force from the sub motor  91  is blocked, and the skew correction of the sheet is executed with the registration rollers  35  contacting the leading edge of the sheet. 
     It is noted that, when a predetermined time period elapses after the sheet is detected by the sensor D 2 , the registration rollers  35  are rotated, and the sheet is conveyed to the image forming unit  60 . 
     In addition, when the sheet is fed from the manual sheet feed tray  41 , the separation roller  73  (and the pickup roller  72 ) and the sheet feed roller  33  are in a state where the transmission of the driving force thereto is blocked by the solenoid  100  for the separation roller and the solenoid  101  for the sheet feed roller, respectively. 
     A carrying speed of the LED printer  5  in the present embodiment is adopted to be lower on a further downstream side in the carrying direction. Specifically, when a sheet is conveyed from the sheet feed cassette  71 , each carrying element such as the sheet feed roller  33 , the registration rollers  35 , and the carrying belt  68  is adopted such that the circumferential velocity thereof is higher in an order of the sheet feed roller  33 , the registration rollers  35 , and the carrying belt  68 . Namely, when the circumferential velocities of the sheet feed roller  33 , the registration rollers  35 , and the carrying belt  68  are represented by α 1 , β 1 , and γ 1 , respectively, a relationship of α 1 &gt;β 1 &gt;γ 1  is established. 
     The sheet fed from the sheet feed cassette  71  is always in a state pushed at the circumferential velocity α 1  by the sheet feed roller  33  toward the downstream side in the carrying direction. Accordingly, the sheet fed by the sheet feed roller  33  is conveyed while slightly slipping between the registration rollers  35 . Namely, the sheet is conveyed at a velocity higher than the actual circumferential velocity β 1  of the registration rollers  35 . 
     Thus, a carrying speed for the sheet that has been made higher by the sheet feed roller  33  is represented by β 2 . 
     In other words, the carrying speed by the registration rollers  35  for the sheet fed from the sheet feed cassette  71  is actually conveyed not at the velocity β 1  but at the velocity β 2 . 
     Meanwhile, the sheet fed from the manual sheet feed tray  41  is conveyed to the image forming unit  60  by the registration rollers  35  that are rotated after the sheet is placed on the tray portion  41   b  of the manual sheet feed tray  41 . The sheet is conveyed due to the rotation of the registration rollers  35  after being placed on the tray portion  41   b  of the manual sheet feed tray  41 , and therefore the circumferential velocity β 1  of the registration rollers  35  corresponds to the carrying speed for the sheet. Namely, the carrying speed by the registration rollers  35  is β 2  for the sheet fed from the sheet feed cassette  71 , and β 1  for the sheet fed from the manual sheet feed tray  41  (β 2 &lt;β 1 ). 
     When a sheet is fed from the manual sheet feed tray  41 , by setting the carrying speed by (circumferential velocity of) the registration rollers  35  to β 2 , the carrying speed for the sheet fed from the manual sheet feed tray  41  can be made identical to the carrying speed for the sheet fed from the sheet feed cassette  71 . Thereby, carrying speeds in carrying the sheet to the image forming unit  60  are the same between the sheet fed from the manual sheet feed tray  41  and the sheet fed from the sheet feed cassette  71 . Thus, it is possible to avoid positional difference between images formed on the sheet fed from the manual sheet feed tray  41  and the sheet fed from the sheet feed cassette  71 . Further, in the LED printer  5  configured to sequentially form four sorts of color images (yellow, magenta, cyan, and black) in the present embodiment, it is possible to prevent positional deviations that might be caused among the respective color images. 
       FIG. 4  is a flowchart showing operations to be executed by the LED printer  5  in the present embodiment. Firstly, it is determined in S 1  whether a button to start printing is pressed (S 1 ). When the button to start printing is pressed (S 1 : Yes), the present process goes to S 2 , in which it is determined whether a sheet is fed from the manual sheet feed tray  41  (S 2 ). 
     When it is determined that a sheet is fed from the manual sheet feed tray  41  (S 2 : Yes), it is determined whether the sensor D 2  is put into an ON state where a sheet is placed on the tray portion  41   b  (S 3 ). When the sensor D 2  is put into the ON state (S 3 : Yes), the present process goes to S 4 , in which the number of revolutions of the sub motor  91  is switched to set the circumferential velocity of the registration rollers  35  to  02  (S 4 ). Subsequently, it is determined whether the sensor D 3  is put into an ON state where the sheet is carried by the registration rollers  35  to the image forming unit  60  (S 5 ). When the sensor D 3  is put into the ON state (S 5 : Yes), the present process goes to S 6 , in which an image forming operation is performed (S 6 ). 
     Meanwhile, in the step S 2 , when it is determined that a sheet is not fed from the manual sheet feed tray  41  (S 2 : No), the present process goes to S 7 , in which a sheet is fed from the sheet feed cassette  71  (S 7 ). Subsequently, it is determined whether the sensor D 1  is put into an ON state where the sheet is fed to the registration rollers  35  by the sheet feed roller  33  (S 8 ). When the sensor D 1  is put into the ON state (S 8 : Yes), the registration operation is performed (S 9 ). Thereafter, in S 10 , the number of revolutions of the sub motor  91  is switched to set the circumferential velocity of the registration rollers  35  to β 1  (S 10 ). Next, the process goes to the aforementioned step S 5 . 
     In the control device  80  of the present embodiment configured as above, the circumferential velocity of the registrations rollers  35  is controlled depending on whether the sheet is fed from the sheet feed cassette  71  or from the manual sheet feed tray  41 . Specifically, when the sheet is fed from the sheet feed cassette  71 , the registration rollers  35  are driven at the normal circumferential velocity β 1 . Meanwhile, when the sheet is fed from the manual sheet feed tray  41 , the registration rollers  35  are driven at the circumferential velocity β 2  a little higher than β 1 . Namely, the LED printer  5  of the present embodiment is configured such that velocity ratios of the circumferential velocity of the carrying belt  68  to the registration rollers  35  are different between a case where the sheet is fed from the sheet feed cassette  71  and a case where the sheet is fed from the manual sheet feed tray  41 . 
     In the present embodiment, a technique has been described, in which the circumferential velocity of the registration rollers  35  is switched between the case where the sheet is fed from the sheet feed cassette  71  and the case where the sheet is fed from the manual sheet feed tray  41 . However, the present invention is not limited to the aforementioned embodiment. For example, two or more sheet feed cassettes  71  may be provided. Further, two or more sheet feed rollers  33  may be provided. In any cases, by changing the circumferential velocity of the registration rollers  35  as required, carrying speeds to feed a sheet to the image forming unit  60  are adopted to be the same, and thus it is possible to prevent positional difference between respective images formed on sheets fed in different ways and positional deviations among respective images of the four colors formed on a sheet. 
     Hereinabove, the embodiments according to aspects of the present invention have been described. The present invention can be practiced by employing conventional materials, methodology and equipment. Accordingly, the details of such materials, equipment and methodology are not set forth herein in detail. In the previous descriptions, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., in order to provide a thorough understanding of the present invention. However, it should be recognized that the present invention can be practiced without reapportioning to the details specifically set forth. In other instances, well known processing structures have not been described in detail, in order not to unnecessarily obscure the present invention. 
     Only exemplary embodiments of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.