Abstract:
An image-recording drum apparatus includes a rotatably driven clamping drum ( 100 ), means ( 160 ) for the fastening of a recording medium (M) on the mantle ( 110 ) of the clamping drum and a recording unit ( 200 ) which is stationary relative to the direction of rotation of the clamping drum and records on the recording medium (M) fastened onto the mantle of the rotating clamping drum ( 100 ) image information fed thereto in the form of electrical signals. Mounting means ( 120 ) are provided in the interior of the clamping drum ( 100 ) for supporting a supply of recording medium (M) wound up into a roll ( 130 ). The clamping drum ( 100 ) has a slit ( 140 ) in its mantle ( 110 ) through which the recording medium (M) can be guided from the interior of the clamping drum ( 100 ) to its mantle ( 110 ) and fastened thereon. The feeding of the recording medium from the interior of the clamping drum is on the one hand constructively especially simple and advantageous and on the other hand permits the cutting of the recording medium only after the recording of the image information to the respectively required exact length without generating clippings. The picture format can thereby be arbitrarily varied within the available length of the clamping drum circumference which permits a very flexible and economical operation of the recording apparatus (FIG.  1 ).

Description:
FIELD OF THE INVENTION 
     The invention relates to a device for the recording of image information on a planar recording medium. In particular, the invention relates to a device for the production of pictures by printing or by projecting image information onto a photographic recording material. 
     BACKGROUND ART 
     Recording drum devices generally include a rotating clamping drum for the recording medium and a recording unit which is stationary relative to the rotation movement of the clamping drum, which unit consists of one or more recording heads which are displaceable parallel to the axis of one or more recording head fields which extend essentially parallel to the axis of rotation of the clamping drum. The recording of image information is carried out point by point, whereby the whole surface of the recording material mounted on the clamping drum is passed over on the one hand by rotation of the clamping drum and on the other hand by displacement parallel to the clamping drum axis of the recording heads or the recording head fields extending across the width of the clamping drum. Recording drum devices of this type are used, for example, for photographic recording processes by way of, for example, light diode exposure of photosensitive copier material or film, and for electrostatic printing processes, as well as for ink jet printing processes. 
     In the previously known recording drum devices of this type, the recording medium depending on the technology either paper or photographic copy material adapted to the intended use—is manually or automatically fed from the outside to the clamping drum and appropriately fixed on the mantle surface thereof. The recording medium must thereby always be cut first to the length corresponding to the drum circumference. If the length of the clamped-on recording material section does not correspond with the length of the image to be recorded or the total length of the images to be recorded, measured in circumferential direction of the clamping drum, cuttings and, thus, waste result. 
     SUMMARY OF THE INVENTION 
     This disadvantage is now to be overcome by the present invention and a drum recording arrangement of the generic type is to be further improved accordingly such that clippings-derived waste is avoided. Moreover, the automatic feeding of the recording medium into the clamping drum is to be simplified. 
     According to the principle idea of the invention, the recording medium is fed from the inside of the clamping drum onto its mantle and fastened thereon. This on the one hand results in an especially simple and advantageous construction and allows on the other hand the cutting of the recording medium to the respectively required exact length after the recording of the image information, without generating clippings. The image format can thereby be arbitrarily varied within the available length of the clamping drum circumference, which permits a very flexible and economical operation of the recording device. Of course, several pictures can also be recorded thereby in one step, as long as their total length does not exceed the circumference of the clamping drum. The physical separation of the recorded pictures into individual pictures can thereby take place even on the clamping drum itself (after completed recording) or in a separate operating step. 
     The recording arrangement in accordance with the invention is especially suited for use in photographic printers, as well as minilabs, and in high performance ink jet printers. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is further described in the following by way of the drawing. It shows: 
     FIG. 1 is a complete schematic illustration of the parts relevant to the invention of a first embodiment of the recording drum device in accordance with the invention, 
     FIGS. 2 to  5  each a detailed portion of the recording arrangement of FIG. 1 in four characteristic operational phases, 
     FIGS. 6 to  7  each a schematic overview illustration of a second embodiment in two views rotated relative to each other by 180° and 
     FIGS. 8 to  12  each a schematic sectional illustration of the recording arrangement of FIG. 6 in five characteristic functional phases. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As is apparent from the complete illustration in FIG. 1, the recording device includes a clamping drum identified in general by  100  and a recording unit identified in general by  200  as well as an electronic control  300 , which controls all movement sequences and functions of the device. 
     The clamping drum  100  has a cylindrical mantle  110  and is driven by a drive motor  111  controlled by the control  300  for rotation about its axis A in direction of the arrow D. 
     The recording unit  200  positioned above the clamping drum  100  which is positioned in a not illustrated frame stationary relative to the rotation movement of the clamping drum includes in this embodiment six recording heads  201  to  206  positioned in direction of rotation one behind the other, which are mounted on a common carrier  210 . The carrier  210  is displaceably supported on two slide rods  221  and  222  and is linearly movable by way of a spindle  230  driven by a spindle motor  231 . In this matter, the recording heads  201  to  206  can be adjusted forward and backward together in the direction parallel to the axis of rotation A of the clamping drum  100  and controlled by the control  300 . 
     The recording heads  201  to  206  can be differently constructed depending on the purpose of the device. They can be, for example, ink jet print heads or point-form light sources for photographic projection. Especially in the latter case, one or more linear arrays (fields) of recording heads can be provided instead of the transversely moveable recording heads, which extend parallel to the axis of rotation A of the clamping drum and cover the whole active width thereof. Such linear arrays of recording heads can typically be formed by rows of light diodes. Recording heads or arrays of recording heads for different recording technologies are known per se and, therefore, do not need to be further described for the person skilled in the art. 
     A coaxial clamping mandrel  120  is found in the interior of the clamping drum  100 , onto which is mounted a storage roll  130  of recording medium M, for example, printing paper of suitable quality. A slit  140  is provided in the mantle  110  of the clamping drum  100  which connects the interior of the clamping drum  100  with its exterior. A redirecting roller  151  is recessed at the forward side of the slit  140  in the direction of rotation of the clamping drum so that it is flush with the surface of the mantle  110 . A pair of clamping rollers  152  and  153  are located below the slit  140  and somewhat displaced against the direction of rotation. A clamping arrangement  160  is provided at the mantle at the rearward side of the slit  140  in direction of rotation of the clamping drum, which clamping arrangement is used for the tightening of the recording medium M on the mantle  110  of the clamping drum  100 . The clamping arrangement  160  includes two carrier arms  161  and  162  pivotally mounted to both sides of the mantle  110  and a clamping bar  163  connecting them, which extends transverse across the width of the clamping drum  100  or its mantle  110 . Further mounted to the two carrier arms  161  and  162  is a cutting arrangement in the form of a knife bar  170  extending across the mantle  110  which is moveable together with the clamping bar  163 . The clamping bar  163  is normally pressed against the surface of the mantle  110  by not-illustrated springs and thereby clamps the recording medium M found thereunder onto the mantle  110  of the clamping drum  100 . 
     An activating arrangement  180  is provided, for example, opposite the recording unit  200  and stationary in a not-illustrated frame, which operates the clamping arrangement  160  and the cutting arrangement  170  controlled by the control  300 , when the clamping drum  100  is in a defined position of rotation in which the activating arrangement  180  is opposite the clamping arrangement  160  and can be brought into engagement therewith. At the same location, a drive arrangement  190  is provided also stationary in a not-illustrated frame. which in the mentioned position of rotation of the clamping drum  100  can be brought into engagement with the recording medium M on the mantle  110 , under control of the control  300 , and functions to advance the recording medium M, in a manner to be described, in the direction of rotation of the clamping drum  100  relative to the mantle  110  thereof. The drive arrangement  190  is only symbolically indicated in FIG.  1  and details are apparent from FIGS. 2 to  5 . 
     As is shown in the detailed illustration of FIG. 2, the drive arrangement  190  essentially includes a drive roller  192  rotatably supported in a pivotable frame  191 , which roller is driven by means of a belt  193  by a motor  194  connected with the control  300 . The pivotable frame  191  is mounted stationary in a not-illustrated frame and can be moved to and from the mantle  110  by an only symbolically indicated excenter mechanism  195 - 196 , whereby the drive roller  192  comes into engagement with or is lifted off the recording medium M located on the mantle. The clamping arrangement  160  and the cutting arrangement  170  connected therewith are also actuated by the same excenter mechanism  195 - 196 . The excenter mechanism  195 - 196  is driven by a not-illustrated stationary motor which in turn is connected with the control  300  and controlled thereby. 
     The recording device functions as follows: 
     After a storage roller  130  of recording medium M is mounted on the clamping mandrel  120  in the interior of the clamping drum  100 , the start of the band-shaped recording medium M is guided between the clamping roller pair  152 - 153  and through the slit  140  to the exterior and about the mantle  110  of the clamping drum  100 , and fastened by way of the clamping arrangement  160 . The drive arrangement  190  is in its inactivated position wherein the draft roller  192  is lifted off the mantle  110 . The recording medium M is thereby fastened onto the clamping drum  100  and the device is ready for the recording process (FIG.  2 ). 
     The clamping drum  100  is now rotated together with the recording medium M in the direction of rotation of the arrow D and the image information to be recorded is recorded by way of the recording unit  200  on the portion of the recording medium M located on the mantle  110  or a part thereof and in a manner known per se. When the recording process is completed, the clamping drum  100  is stopped in the aforementioned defined position of rotation (parked position). 
     The drive arrangement  190 , as illustrated in FIG. 3, is now lowered onto the mantle  110  so that the drive roller  192  comes into engagement with the recording medium M on the mantle. At the same time, or immediately thereafter, the clamping arrangement  160  is lifted off the mantle  110 , together with the knife bar  170 , so that the recording medium M is at this location only held on the mantle  110  by the drive roller  192 . 
     The written-on (image-carrying) section of the recording medium M is now ejected (FIG.  4 ). The drive roller  192  is therefor rotated and the recording medium band M advanced in direction of rotation of the clamping drum  100  under the knife bar  170  until the rearward end of the described section is located under the knife bar  170 . 
     The clamping arrangement  160  is thereafter once again pressed against the mantle  160  together with the knife bar  170  connected therewith and the drive arrangement  190  is simultaneously or immediately thereafter lifted off the mantle  110 . By the downward movement (radially inwardly relative to the drum) of the clamping arrangement  160  and the knife bar  170 , the written-on section of the medium is cut off and the new beginning of the still not printed-on medium is clamped on the clamping drum. The arrangement is now ready for the next recording process (FIG.  5 ). 
     FIGS. 6 to  12  show a second embodiment of the recording device wherein the clamping drum rotates with constant speed during the whole recording period. This has the advantage that the down times otherwise resulting from the deceleration and acceleration of the clamping drum are obviated. The clamping drum need only be stopped for the initial loading and for the reloading of recording medium. 
     The recording device of FIGS. 6 to  12  corresponds in its principle construction to the one of FIGS. 1 to  5 . Identical or corresponding parts are therefore provided with the same reference numeral. The essential difference resides in the replacement of the clamping arrangement  160  in this embodiment with a suction arrangement  460  so that the cutting arrangement  170  positioned on the clamping drum, as well as the stationary activating arrangement  180  and the stationary drive arrangement  190  are obviated. A further essential difference consists in a stationary cylindrical guide mantle  400  which coaxially surrounds the clamping drum  100  or its mantle  110 , and in this manner forms a guide channel for the recording medium M between itself and the mantle  110 . The suction arrangement  460  is of conventional construction and is connected to a not-illustrated vacuum source which is operably connected with the control  300  and activated or deactivated thereby and can be reversed in its effect thereby. When the vacuum source is activated, the end of the recording medium M above the suction arrangement  460  is fastened on the mantle  110  of the clamping drum  100  because of the suction effect and, upon deactivation of the vacuum source, the recording medium is released. Upon reversed suction, the end of the recording medium M is actively lifted off the mantle  110  because of the blowing effect. 
     The guide mantle  400  is provided with a movable window  410  in the region of the recording unit  200 , which window is movable back and forth by way of a not-illustrated drive parallel to the axis of rotation of the clamping drum  100  between an open position and a closed position. In the open position (FIGS. 6 and 8) the recording medium M located below the recording heads of the recording unit  200  is accessible and in the closed position the movable window  410 , just like the rest of the guide mantle  400 , forms a guide surface for the recording medium M. 
     About diagonally opposite the movable window  410 , a switch  420  is inset into the guide mantle  400  (FIG.  7 ). This switch consists essentially of two coaxial guide surfaces  421  and  422  which have an essentially cylindrical curvature and which form a switch channel  423  therebetween. The two guide surfaces  421  and  422  and therefore the whole switch  420  are pivotally supported at their rear ends for pivoting about a stationary axis W parallel to the axis of rotation of the clamping drum, so that their forward ends can be pivoted regularly inward or outward. A switch drive is provided for this pivoting movement of the switch  420  which drive is symbolically indicated by two elements  424  and cooperates with the control  300 . At a rear end of the switch  420 , the switch channel  423  opens into a stationary removal channel  430  adjacent the switch  420  (FIGS. 8 to  12 ). 
     In the radially outer normal position of the switch  420 , its inner guide surface  421  is aligned with the guide mantle  400  (FIG.  8 ), in the radially outer unloading position, the inner guide surface  421  practically lies on the mantle  110  of the clamping drum  100  and the outer guide surface  422  is aligned at its free forward end essentially with the guide mantle  400  (FIG.  10 ). 
     The free, forward end  426  of the inner guide surface  421  of the switch  420  is further formed as a cutting knife in a manner known per se which cooperates with the oppositely located edge  401  of the guide mantle  400  and together therewith forms a cutting arrangement for the recording medium M (FIG.  11 ). The functioning of this variant of the recording arrangement is as follows: 
     After a storage roll  130  of recording medium M is mounted on the clamping mandrel  120  in the interior of the clamping drum  100 , the beginning of the band-shaped recording medium M is clamped between the clamping roller pair  152 - 153 , guided through the slit  140  to the exterior, guided around the mantle  110  of the clamping drum  100  and fastened by way of the vacuum arrangement  460 . Simultaneously or subsequently, the moveable window  410  is moved into the open position (FIG. 6) and the switch  420  is pivoted into its normal position (FIG.  8 ). The recording medium M is thereby fastened on the clamping drum  100  and the device is ready for the recording process. 
     The clamping drum  100  is now rotated together with the recording medium M in direction of the arrow D and the image information to be recorded is recorded by way of the recording unit  200  on the section of the recording medium M found on the mantle  110  or on a part thereof in a manner known per se (FIG.  8 ). 
     When the recording process is finished, the recording unit  200  is axially displaced into a parking position and the movable window  410  is again closed (FIG.  9 ). The clamping roller  100  continues to rotate with constant speed. 
     When the clamping drum  100  arrives at a position of rotation in which the suction arrangement  460  is located just before the switch  420  (FIG.  9 ), the switch  420  is pivoted into its inner discharge position and the vacuum arrangement  460  is deactivated or reversed in its effect. The remaining portion of the recording medium M is thereby lifted off the mantle  110  of the clamping drum  100  and guided into the switch channel  423 . The switch  420  then during a further rotation of the clamping drum  100  guides the recording medium M into the discharge channel  430 . The recording medium M is therefore, figuratively speaking, in a way “peeled off” the clamping drum  100  (FIG.  10 ). 
     After the image-carrying part of the recording medium M has been detached from the clamping drum  100 , the switch  420  is swiveled back into its outer, normal position. The forward, free end of the inner guide surface  421  of the switch  420  which is formed as a cutting arrangement thereby severs the image-carrying portion from the remaining recording medium still found on the clamping drum (FIG.  11 ). The image-carrying portion is guided through the removal channel  430  to an external not-illustrated arrangement for the further processing, for example, separation into individual pictures. 
     Recording medium M is now pulled from the storage roller  130  by way of the clamping rollers  152  and  153  driven by a not-illustrated drive motor (FIG. 12) and further advanced until the forward end reaches the engagement area of the suction arrangement  460 . The latter is subsequently again activated and the recording medium M so fixed on the clamping drum. The arrangement is now again ready for the next recording step (FIG.  8 ). 
     It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.