Abstract:
A scanner-equipped apparatus includes a combination of a base unit such as a printer unit, personal computer or word processor incorporating a printer unit and a scanner unit. The printer unit and the scanner unit can operate as automatic sheet feeder type apparatus, respectively. The scanner unit can be used as a handy scanner in the state detached from the base unit. The basic unit and the scanner unit are disposed substantially in upstanding posture in parallel with each other, wherein the scanner unit is removably combined with the base unit so that the scanner unit can be used as the handy scanner. A sheet transporting path for the scanner is formed between confronting surfaces of the base unit and the scanner unit. The sheet feeding mechanism for the scanner unit is so implemented as to be used intact as a driving mechanism for the handy scanner. The scanner-equipped apparatus can be realized inexpensively in a simplified mechanical structure while ensuring enhanced manipulatability.

Description:
This is a Divisional of application Ser. No. 08/964,257 filed Nov. 4, 1997, and the entire disclosure of this prior application is considered to be part of the disclosure of the accompanying application and is hereby incorporated by reference therein. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to an apparatus equipped removably with a scanner unit (also referred to as a scanner-equipped apparatus) in which a base apparatus or base unit such as a personal computer, a word processor or the like incorporating therein a printer unit is combined detachably with a scanner unit so that the scanner unit itself can also be used independently as a so-called handy scanner. By way of example, as a typical one of the scanner-equipped apparatus, there may be mentioned a printer/scanner combination apparatus which is composed of a printer unit and a scanner unit combined integrally and mutually detachably and which provides advantages that the space demanded for the installation of the apparatus can be reduced when compared with the space required for installing separately the printer unit and the scanner unit and that the printer/scanner combination apparatus can be manufactured at relatively low costs. Thus, the present invention is particularly concerned with a printer/scanner combination apparatus which includes a printer unit and a scanner unit combined detachably such that the scanner unit can be detached to be used as the handy scanner, to thereby enhance the utility of the scanning function while ensuring high manipulatabilty and serviceability for maintenance of the apparatus. 
   2. Description of Related Art 
   In recent years, in the field of data processing with the personal computer, there arises an increasing tendency of processing image, graphics and the like data, which is accompanied with rapid spreading of the scanner apparatus for fetching the image data. 
   In general, the personal computer system is comprised of a main body, a display unit, a keyboard, a printer, etc. Consequently, for the installation of the personal computer system, a considerably large space is demanded. Such being the circumstances, user who bought a scanner will often bother his or her head over the place where the scanner is to be installed. Furthermore, although the scanner is commercially available at remarkably low price at present, purchase of the scanner means not a little burden on the consumers. 
   Under the circumstances, there have been developed various scanner-equipped printer apparatuses in which a sensor is mounted on a carriage of the printer, wherein image reading operation is carried out by making use of the sheet feed mechanism of the printer for feeding an image document sheet (i.e., paper or the like sheet having text, a picture or graphics recorded thereon) in efforts to implement the scanner at low costs while mitigating the space demand for the installation of the scanner. 
   However, in the case of the conventional scanner-equipped printer apparatuses known heretofore, the sheet feeding mechanism is used in common for both the scanning function and the printing function. Consequently, it has been impossible to use both the functions at the same time. Further known is such a printer/scanner combination apparatus in which the reader unit provided for realizing the scanning function can be detached so as to be used as a so-called handy scanner. However, because the conventional reader unit includes no driving mechanism, the handy scanner can be operated only manually. In order to allow the handy scanner to operate automatically, it is required to provide a driving mechanism dedicated for the handy scanner. However, in the conventional apparatus, the driving mechanism for the handy scanner is left unused in the state in which the handy scanner is mounted on the printer unit. Thus, in the conventional printer/scanner combination apparatus, the efficiency of hardware utilization is low, which in turn means that the cost-performance of the conventional printer/scanner combination apparatus is poor. 
   SUMMARY OF THE INVENTION 
   In the light of the state of the art described above, it is an object of the present invention to provide a scanner-equipped apparatus which includes automatic sheet feeders separately for a base unit such as a printer unit or personal computer or word processor incorporating a printer unit and a scanner unit, respectively, so that the printing function and the scanning or reading function can be made use of independently and separately from each other. 
   Another object of the present invention is to provide a scanner-equipped apparatus which allows a scanner unit to be detached for use as a handy scanner which is capable of operating automatically with high efficiency. 
   In view of the above and other objects which will become apparent as the description proceeds, there is provided according to a general aspect of the present invention a scanner-equipped apparatus of such a basic structure in which a base unit such as a printer, personal computer, word processor or the like and a scanner unit are disposed substantially vertically or in upstanding posture in parallel with each other, wherein the scanner unit is removably or detachably combined with the base unit so that the scanner unit can be used as a handy scanner. A sheet transporting path (or document sheet transportation path) for the scanner is formed between confronting surfaces of the base unit and the scanner unit when they are combined each other. Besides, the sheet feeding mechanism for the scanner unit is so implemented as to be used intact as a driving mechanism for the handy scanner. Thus, the scanner-equipped apparatus according to the present invention can be realized in a simplified mechanical structure while ensuring enhanced manipulatability. 
   Fundamental features of the invention as well as preferred modes for carrying out the invention will be summarized below. 
   According to a general or basic feature of the present invention, the apparatus equipped removably with a scanner or the scanner-equipped apparatus includes a base unit and a scanner unit which can be removably mounted on the base unit. The base unit includes at least a controller, a part of sheet transporting mechanism and a scanner mounting means for mounting detachably the scanner unit. The scanner unit includes at least a reading unit, the remaining part of the sheet transporting mechanism and an engaging means adapted for engaging the scanner mounting means for thereby securing the scanner unit onto the base unit. 
   In a preferred mode for carrying out the invention, the scanner unit may be so implemented as to be capable of operating as a handy scanner in the state where the scanner unit has been detached from the base unit. 
   In another preferred mode for carrying out the invention, the base unit may be a printer unit. 
   In yet another preferred mode for carrying out the invention, the base unit may be of an automatic sheet feeding type and include a first sheet transporting path extending substantially vertically, while the scanner unit may be of an automatic sheet feeding type and include a second sheet transporting path extending substantially vertically, wherein the first and second sheet transporting paths are so disposed as to extend substantially in parallel and adjacent to each other. 
   In a further preferred mode for carrying out the invention, the sheet transporting path or document sheet transporting path for the scanner unit may be defined by confronting surfaces of the base unit and the scanner unit in the state in which the scanner unit is mounted on the base unit. 
   In a yet further preferred mode for carrying out the invention, the scanner-equipped apparatus may be so arranged that a pick roller is disposed at a location upstream of the second sheet transporting path of the scanner unit as viewed in the sheet transporting direction, while feed rollers are disposed at locations downstream of the second sheet transportation path for the scanner unit as viewed in the sheet transporting direction. 
   In a still further preferred mode for carrying out the invention, the pick roller may be made of a material having low hardness, wherein auxiliary rollers which are made of a material having high hardness may be disposed at sides of the pick roller, respectively, for thereby protecting the pick roller when the scanner unit is used as the handy scanner. 
   In yet further preferred mode for carrying out the invention, the auxiliary rollers may be disposed at locations outside of a reading region of the scanner unit. 
   In another preferred mode for carrying out the invention, the auxiliary rollers may be disposed in the vicinity of the pick roller, while grooves may be provided in a surface of the base unit facing in opposition to the auxiliary rollers. 
   In yet another preferred mode for carrying out the invention, a mark indicating a reading region may be provided at least on one of a front side portion and a rear side portion of the scanner unit, while a mark indicating a reading position may be provided on a lateral side portion of the scanner unit. 
   In still another preferred mode for carrying out the invention, a cable for electrically coupling the scanner unit to the base unit may be led out from a location positioned at a lateral surface of the scanner unit. 
   In a further preferred mode for carrying out the invention, a cable for electrically coupling the base unit to the scanner unit may be led out from a location positioned at a lower portion of a lateral surface of the base unit. 
   In a yet further preferred mode for carrying out the invention, the sheet transporting mechanism for the scanner unit may include feed rollers and a driving motor for driving the feed rollers so that the scanner unit can operate as a handy scanner of an automatically running type by using the feed rollers. 
   In a still further preferred mode for carrying out the invention, the base unit may include a printer unit, wherein a sheet transporting mechanism of the printer unit is comprised of a feed roller and a driving motor for driving the feed roller. Further, a sheet transporting mechanism for the scanner unit may be comprised of a sheet transporting roller and an encoder for detecting an amount of rotation of the sheet transporting roller so that the scanner unit can be operated as a manual type handy scanner. 
   In another preferred mode for carrying out the invention, either one of engaging portions of the base unit and the scanner unit may be constituted by a pivotal shaft for allowing the scanner unit to rotate or swing frontwards, while the other engaging portion may be implemented as a groove or alternatively as a recess for receiving and holding snugly the pivotal shaft. 
   In yet another preferred mode for carrying out the invention, the scanner-equipped apparatus may further include a lock means including a claw and a projecting member adapted to engage with the claw for thereby locking the scanner unit in the state mounted on the base unit. 
   In still another preferred mode for carrying out the invention, the scanner-equipped apparatus mentioned above may further be so arranged as to include a rotation limiting stopper means for preventing the scanner unit from swinging excessively frontwards upon detachment of the scanner unit from the base unit. 
   In still another preferred mode for carrying out the invention, the scanner-equipped apparatus may additionally be so arranged as to include a deviation preventing stopper means for preventing the scanner unit from displacing upwardly in the state in which the scanner unit is mounted on the base unit. 
   In still another preferred mode for carrying out the invention, the scanner-equipped apparatus described above may be so arranged as to include a sheet feeding means formed in a wedge-like shape as viewed in a vertical section by a pair of sheet guides disposed in opposition to each other so that a space defined between the pair of sheet guides becomes gradually narrower toward a sheet withdrawal port, and an offset means provided for at least one of the paired sheet guides for limiting stepwise the moving of the sheet toward the sheets withdrawal port. 
   The above and other objects, features and attendant advantages of the present invention will more easily be understood by reading the following description of the preferred embodiments thereof taken, only by way of example, in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the course of the description which follows, reference is made to the drawings, in which: 
       FIGS. 1A and 1B  are views showing generally an outer appearance of a printer/scanner combination apparatus according to an embodiment of the present invention, wherein  FIG. 1A  shows the same in a state in which a reader unit is combined with a printer unit so as to be capable of operating as an automatic paper feed type scanner unit, and  FIG. 1B  shows the reader unit dismounted from the printer unit so that the reader unit can be used as a handy scanner on a guide plate; 
       FIG. 2  is a schematic sectional view of a scanner unit showing a document sheet feeding mechanism for the reader unit; 
       FIG. 3  is a developed view showing a mount/detachment mechanism for the reader unit; 
       FIG. 4  is a bottom plan view of the reader unit; 
       FIG. 5  is a top plan view of the reader unit; 
       FIG. 6  is a perspective view showing the reader unit; 
       FIG. 7  is a sectional view showing schematically an optical mechanism incorporated in the reader unit; 
       FIG. 8  is a schematic sectional view showing two kinds of sheet transportation paths are provided separately; and 
       FIG. 9  is a schematic sectional view of a document sheet feeding tray in a printer/scanner combination apparatus according to an embodiment of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Now, the present invention will be described in detail in conjunction with what is presently considered as preferred or typical embodiments thereof by reference to the drawings. In the following description, like reference characters designate like or corresponding parts throughout the several views. Also in the following description, it is to be understood that such terms as “left”, “right”, “top”, “bottom”, “front”, “rear”, “lateral”, “vertical”, “clockwise”, “counterclockwise” and the like are words of convenience and are not to be construed as limiting terms. Further, definition of terms used herein will be made. With the phrase “paper sheet”, it is contemplated to encompass a blank sheet of paper and forms such as letterhead, labels, envelopes, etc. on which texts, graphics, pictures are to be printed. On the other hand, with the phrase “document sheet”, it is intended to encompass such sheets or papers on which text, graphics, picture, etc, are visibly recorded. Of course, photograph and the like are equally covered by the phrase “document sheet”. 
     FIGS. 1A and 1B  are views showing generally an outer appearance of a printer/scanner combination apparatus according to an embodiment of the present invention, wherein  FIG. 1A  shows the same in the state in which a reader unit  1  is combined with a printer unit  3  so as to be capable of operating as an automatic paper feed type scanner unit, and  FIG. 1B  shows the same in the state in which the reader unit  1  is dismounted from the printer unit  3  so that the reader unit  1  can be used as a handy scanner on a guide plate  2 . 
   In  FIG. 1A , major portions of a mechanical structure of the printer unit  3  are located at the back side of the printer/scanner combination apparatus and thus they are invisible in this figure. The printer unit of the printer/scanner combination apparatus shown in  FIG. 1A  is implemented in a vertical standing structure, wherein a paper sheet is discharged through a printed paper delivery port  5  after having been printed by a printing means (not shown). The reader unit  1  is equipped with a pick roller, a reading window and feed rollers etc., at a rear surface (which forms a bottom surface when the reader unit  1  is used as the handy scanner). The scanner unit is implemented also in a substantially upstanding structure, wherein a document sheet fed from a document sheet feeding tray  6  is discharged from a scanned document sheet delivery port  7  after data (image data) on the document sheet have been read out by the reader unit  1 . Parenthetically, an L-shaped auxiliary guide  6   a  is provided in association with the document sheet feeding tray  6  for the purpose of supporting a pile of document sheets of large sizes. The L-shaped auxiliary guide  6   a  may be so implemented as to be capable of supporting the document sheets of various sizes with a simplified structure. 
   Referring to  FIG. 1B , in the state where the reader unit  1  is detached from the printer unit to be used as the handy scanner, as shown in the figure, the reader unit  1  is electrically coupled to the printer unit  3  by means of a cable (not shown) through which power supply as well as transmission of control signals and data can be realized between the reader unit  1  and the printer unit  3 . The guide plate  2  is formed of a transparent material such as acrylic resin or the like and ordinarily adapted to be disposed on a document sheet. The reader unit  1  is so dimensioned as to be snugly fit within a guide frame of the guide plate  2 . By moving slideably the reader unit  1  manually or automatically over the guide plate  2 , a document sheet disposed beneath the guide plate is scanned, whereby the corresponding image data is read by the reader unit  1 . A reading position mark  1   a  is indicated at a lateral side of the reader unit  1 , while reading area marks  1   b  are provided at the front, and rear sides, respectively. These marks serve to aid the user in positioning the reader unit  1  within the reading region of the document sheet with accuracy in particular when the original reading operation is to be carried out without resorting to the use of the guide plate. 
     FIG. 2  is a schematic sectional view of the scanner unit showing a document sheet feeding mechanism of the reader unit  1 . A document sheet transportation path for the scanner unit is formed between the printer unit and the reader unit  1  when the reader unit  1  is mounted on the printer unit. The reader unit  1  is equipped with a pick roller  10  and a feed roller  11  which are rotationally driven by a driving motor  8  through the medium of a driving gear train generally denoted by reference numeral  9 . From a layer or pile of loose document sheets  12  placed on the document sheet feeding tray  6 , a document sheet is withdrawn downwardly on a sheet-by-sheet basis through cooperation of the pick roller  10  and the document sheet separating member  13 . The document sheet as withdrawn from the pile  12  is detected by a document sheet detection sensor  14  for making preparation for the data reading operation, which is followed by detection of the leading edge of the document sheet by a leading/trailing edge detecting sensor  15 , whereupon image data reading operation is started. Subsequently, upon detection of the trailing edge of the document sheet, the image data reading operation is terminated. The feed roller  11  and a follower roller  16  cooperate to feed the scanned document sheet to a scanned document sheet delivery guide  17 . In this conjunction, it should be mentioned that the scanned document sheet delivery guide  17  may be so implemented as to serve also as a cover for the printed paper delivery port  5  of the printer unit  3  shown in  FIG. 1A . 
     FIG. 3  is a developed view showing a mount/removal mechanism for the reader unit to be used also as the handy scanner. As will hereinafter be described in detail by reference to  FIGS. 4 and 6 , the reader unit  1  is provided with a pivotal shaft receiving groove  18   a , a locking claw receiving groove  20   a  and a stopper groove  21   a , respectively, so that the reader unit  1  can be mounted removably on the printer unit at both sides of the reader unit  1  with high security. Correspondingly, the printer unit  3  is provided with a pivotal shaft  18   b , a locking claw  20   b  and a stopper  21   b  which are adapted to engage with the pivotal shaft receiving groove  18   a , the locking claw  20   b  and the stopper groove  21   a  of the reader unit, respectively. 
   The pivotal shaft receiving groove  18   a  has a bottom opened. Thus, the reader unit  1  can easily be dismounted from the printer unit  3  by rotating or turning the reader unit  1  in the counterclockwise direction, as indicated by an arrow {circle around ( 1 )}, from the mounted state in which the reader unit  1  is inclined in the right-hand direction (indicated by a solid line) to a substantially vertical state (indicated by broken line) and then lifting upwardly the reader unit  1 , as indicated by an arrow {circle around ( 2 )}. Needless to say, the reader unit  1  can be mounted by carrying out the procedures indicated by the arrows {circle around ( 1 )} and {circle around ( 2 )} in the reverse order. In the state where the reader unit  1  is mounted on the printer unit  3 , the reader unit  1  is prevented from the counterclockwise rotation so long as a force of predetermined magnitude is not applied because of the engagement between the locking claw receiving groove  20   a  and the locking claw  20   b . Besides, in addition to the prevention of the counterclockwise rotation of the reader unit  1 , upward move of the reader unit  1  in the mounted state is prevented owing to the mutual engagement of the stopper groove  21   a  and the stopper  21   b . In this manner, the reader unit  1  can be mounted on the printer unit  3  with significantly high security. Moreover, since the rotation stopper  19   a  is formed integrally with the pivotal shaft receiving groove  18   a  of the reader unit  1  and extends downwardly, the rotation of the reader unit  1  can be limited to within a predetermined angular range because the rotation stopper  19   a  is received by the rotation stopper receiving groove  19   b  provided in association with the printer unit  3  upon counterclockwise rotation of the reader unit  1 . In this manner, the reader unit  1  can positively be protected against accidental removal from the printer unit  3  due to inadvertent manipulation of the user. 
     FIG. 4  is a bottom plan view showing the reader unit  1 ,  FIG. 5  is a top plan view showing the same, and  FIG. 6  is a perspective view thereof. As can be seen in  FIG. 4 , a pick roller  22  may be mounted on the bottom surface of the reader unit  1  at a front and center location, while a pair of feed rollers  23  are mounted at right and left positions, respectively, symmetrically relative to the rear center of the reading window  24 . As can be seen in  FIG. 5 , each of the pick roller  22  and the feed rollers  23  is driven rotationally by the driving motor  8  by way of the driving gear train  9 . Thus, when the reader unit  1  is used as the handy scanner, operation of the scanner can be performed automatically by making use of the rotational driving force or torque generated by the electric motor mentioned above. At this juncture, it should be mentioned that the pick roller  22  is usually made of a relatively flexible material of low hardness such as urethane resin. In that case, such situation may occur that the pick roller  22  is collapsed under the gravity of the reader unit and can not support the reader unit. In order to avoid such situation as mentioned above, there is provided an auxiliary rollers  22   a  made of a material of high hardness which serves for supporting the reader unit  1  so that the pick roller  22  does not apply excessive pressure onto the guide plate or the top surface of the document sheet. The auxiliary rollers  22   a  are disposed outside of the reading region  24  in order to protect the surface of the document sheet  12  against injury, as can be seen in  FIG. 4 . In this conjunction, it should be mentioned that the width of the auxiliary rollers  22   a  may be increased and mounted in the vicinity of the pick roller  22  so that the auxiliary rollers  22   a  can rotate freely coaxially with the pick roller  22 . 
     FIG. 7  is a sectional view showing an optical mechanism  25  incorporated in the reader unit  1 . The reading position is defined at the reading window  24  described hereinbefore by reference to  FIG. 4 . Light rays reflected from the document sheet to be read out and impinging into the optical mechanism through the reading window  24  reflections a number of times at a plurality of mirrors  25   a  to be collected by a lens  25   b  and received by a charge coupled device  25   c  which serves for converting the optical information into an electric signal. 
   At this juncture, it should be mentioned that the printer unit and the scanner unit of the printer/scanner combination apparatus according to the instant embodiment of the invention have sheet transportation paths (i.e., the paper sheet transportation path and the document sheet transportation path) provided separately for the printer unit and the scanner unit, respectively. Ordinarily, the printer unit is in the state where a pile of paper sheets is set or placed on the paper sheet feeding tray, while for the scanner unit, various kinds of the document sheets to be scanned or read out are set or placed on the document sheet feeding tray  6  every time the reading operation is desired. In this conjunction, if a transportation path is provided in common to the paper sheet and the document sheet for the printer unit and the scanner unit, as mentioned hereinbefore, troublesome work will be required for exchanging the paper sheets and the document sheets, incurring possibility of the paper sheets and the document sheet being erroneously mixed together. Accordingly, in the case of the printer/scanner combination apparatus according to the instant embodiment of the invention, the paper sheet transportation path and the document sheet transportation path are provided separately for the printer unit and the scanner unit, respectively. Furthermore, it is desirable that the document sheets can be placed at the document sheet feeding tray  6  more easily when compared with the setting of blank paper sheets. To this end, the document sheet transportation path for the scanner unit should be disposed at a position near to the front side of the apparatus, as viewed in  FIG. 1A . 
     FIG. 8  is a schematic sectional view of the printer/scanner combination apparatus in which the two sheet transportation paths (i.e., the paper sheet transportation path and the document sheet transportation path) are provided separately, as mentioned above. In the printer unit  3 , the paper sheet placed as a pile at the paper sheet feeding tray  4  for the printer is automatically transported on a sheet-by-sheet basis along the paper sheet transportation path  30  as indicated by an arrow. After having been printed by a printing head  28 , the printed paper sheet is discharged from the printed paper delivery port  5 . On the other hand, in the scanner unit portion having the reading window  24  mounted on the printer unit, the document sheet placed on the document sheet feeding tray  6  is automatically fed into the reader unit  1  on a sheet-by-sheet basis. The document sheet undergone the reading operation is transported along the document sheet transportation path  31  as indicated by an arrow to be discharged from the document sheet withdrawal port  35 . 
   As can be seen in  FIG. 8 , the sheet transportation paths for the printer unit and the scanner unit are provided substantially in parallel with each other. 
   Since the printer unit and the scanner unit of the printer/scanner combination apparatus according to the instant embodiment of the invention are combined together and disposed at rear and front sides (as viewed in  FIG. 1 ) or at left and right sides, respectively, as viewed in  FIG. 8 , the document sheet feeding tray  6  disposed at the front side (right-hand side as viewed in  FIG. 8 ) may present an obstacle to the setting or positioning of a pile of paper sheets on the paper sheet feeding tray  4  for the printer. To cope with this problem, the document sheet feeding tray  6  should preferably be so implemented as to be pivotally inclined to the front side, as viewed in  FIG. 1  (or to the right-hand side, as viewed in  FIG. 8 ) within a predetermined angular range. It should also be noted that the printer cover/document sheet guide means  29  serves not only as the cover for the printing mechanism of the printer unit but also as the guide for the document sheet which has undergone the reading operation by the scanner unit. Consequently, the printer cover/document sheet guide means  29  should preferably be so implemented that it can be inclined toward the front side or removed in order to facilitate the maintenance of the printing mechanism. 
     FIG. 9  is a schematic sectional view of the document sheet feeding tray in the printer/scanner combination apparatus according to the instant embodiment of the invention. Referring to the figure, a document sheet guide  32  and an auxiliary document sheet guide member  33  are disposed in opposition to each other in such orientation that the space defined between the document sheet guide  32  and the auxiliary document sheet guide member  33  becomes narrower gradually toward a document sheet withdrawal port  35 . To say in another way, the vertical section of the space between the document sheet guide  32  and the auxiliary document sheet guide member  33  presents substantially a wedge-like shape. By virtue of such arrangement, the document sheet is fed automatically into the printer/scanner combination apparatus essentially on a sheet-by-sheet even when a pile of document sheets is placed on the document sheet feeding tray  6 . However, when the number of the document sheets contained in the pile is excessively large, there may take place jamming of the document sheets at or in the vicinity of the document sheet withdrawal port  35  under the weight of the document sheets as piled. To evade this problem, the document sheet guide  32  should preferably be provided with an offset portion  34  in order to prevent the load of all the document sheets piled from being concentrated to the document sheet withdrawal port  35 . In this conjunction, it should be noted that a plurality of such offset portions  34  may be provided although only one offset portion  34  is shown in  FIG. 9 . Additionally, such offset portion may be provided in the auxiliary document sheet guide member  33  as well. Parenthetically, the offset portion is imparted with a lenient inclination so that the document sheet can slidably move downwardly to the document sheet withdrawal port  35 . 
   Many features and advantages of the present invention are apparent from the detailed description and thus it is intended by the appended claims to cover all such features and advantages of the system which fall within the true spirit and scope of the invention. Further, since numerous modifications and combinations will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation illustrated and described. 
   By way of example, in the printer/scanner combination apparatus described above, the driving motor  8  and the feed rollers  11  are incorporated in the reader unit  1  so that the reader unit  1  can be operated independently. However, the present invention is never restricted to the implementation of the reader unit  1  in the form of the handy scanner which can be operated automatically. Furthermore, the driving mechanism may be incorporated in the base unit (printer unit) with the reader unit  1  being constituted by the following roller and the position detecting encoder. In that case, the reader unit can be implemented in a miniaturized structure of light weight. When the handy scanner is manipulated on the guide plate, the cable is likely to provide an obstacle to the manipulation or operation of the handy scanner. Accordingly, the cable interconnecting the reader unit  1  and the printer unit  3  may preferably be secured to lower side portions of the reader unit  1  and the printer unit  3 , respectively, while a cable clamp member for securing the cable to the guide plate may be provided in association with the latter. 
   Accordingly, all suitable modifications and equivalents may be resorted to, falling within the spirit and scope of the invention. 
   As will now be apparent from the foregoing description, it is possible to combine the scanner unit with a base unit such as a printer unit, personal computer, word processor or the like incorporating a printer unit so that the printer unit and the scanner unit can be operated independent of each other. Thus, the space required for installing the base unit and the scanner unit can be reduced significantly. Besides, the scanner unit can be easily detached or removed from the base unit and used as an automatically or manually operated handy scanner essentially without need for provision of any additional means. Thus, the utility efficiency of the printer/scanner combination apparatus can be enhanced remarkably as a whole nevertheless of low manufacturing cost.