text: the present controlled light source device 10 ( fig1 ) for reading x - ray film may include a frame 11 supporting a first roll support 12 , a second roll support 13 and an x - ray reading station 14 including an etched polymer sheet 15 , e . g ., etched plexiglass ™. the frame 11 may be of any suitable construction , typically of angle iron and steel sheeting materials or of polymeric construction . the first roll support 12 is adapted to carry a roll 16 of a composite of web 17 and a plurality of sheets of x - ray film 18 . the web 17 may include a trough 17 a ( fig7 ) that serves to trap the lower edge of the x - ray film adjacent the principal portion 17 b of the web 17 . the trough 17 a may be formed merely by folding a lower portion of the web 17 as shown in fig7 . the web 17 may be of any suitable transparent polymer sheet such as polyethylene or polypropylene , for example having a thickness and strength sufficient to support the x - ray film 18 . the web 17 rides along against the etched polymer sheet 15 . an alternative support is trough 17 c is shown in fig8 . the trough 17 c has a strip 17 c ′ that is secured to web 17 by a two sided adhesive strip 17 c ″. the adhesive strip 17 c ″ serves to space the strip 17 c ′ from web 17 sufficient to permit the x - ray film 18 in the slot 17 c ″′. any suitable mechanism may be used to hold the x - ray films adjacent the web 17 . for example , a pocket or a clamp may be used to secure an edge of the x - ray film to the web . alternatively , a line or filament may be used wherein the line is stretched along the web x - ray composite 17 / 18 . the first roll support 12 ( fig1 ) may be in the form of a power driven shaft 19 . the roll 16 of the web 17 and x - ray film 18 may be mounted for use by placement over the driven shaft 19 . the shaft 19 may be controlled by a power mechanism such as a small electric motor 21 to either permit controlled withdrawing , e . g ., stripping of the composite 17 / 18 from the roll 16 or to provide powered wrapping of the composite 17 / 18 onto the roll 16 . the second roll support 13 may be in the form of a power driven shaft 22 to support the second roll 23 of the web 17 . the shaft 22 may be driven by power mechanism such as a small electric motor 24 . the shaft 22 serves during normal operation to strip the composite of web 17 and x - ray film sheets 18 from roll 16 and wrap the composite 17 / 18 onto roll 23 . the operation of power driven shafts 19 and 22 may be reversed so that the composite of web 17 and x - ray film sheets 18 are stripped from roll 23 and wrapped onto roll 16 . this permits the doctor or 20 radiologist to review again a x - ray film that has already passed the reading station by return of the x - ray film to the reading station 14 . the device 10 includes sensing mechanism 26 that serves to scan the composite of the web 17 and x - ray film 18 . the sensing mechanism 26 may include a plurality of individual sensors 26 a , 26 b , 26 c , and 26 d . the sensing mechanism 26 is disposed downstream of the roll 16 and upstream of the reading station 14 . the sensing mechanism 26 may be a plurality of photoelectric cells operated on any of various principles such as reflective light or a system in which the amount of light passing through the composite is measured . one suitable system is the product available from banner engineering corp . of minneapolis , minn . under the designation mini - beam expert ™. suitable photoelectric cells are described in u . s . pat . nos . 4 , 356 , 393 and 5 , 808 , 256 . the individual sensors 26 a - 26 d may be positioned to read the presence of the x - ray film in the path leading from the roll 16 to the reading station 14 . the sensor 26 a may be placed in a lower location to read the leading edge of the x - ray film and the trailing edge of the x - ray film . the sensor 26 a compiles data defining where an x - ray film 18 begins and ends in the supported position on the web . the sensor 26 b is in a partially elevated position to distinguish between short x - ray film 18 having a vertical dimension of perhaps 10 inches and x - ray film 18 having a vertical dimension greater than 10 inches . the sensor 26 b for example may be placed slightly more than 10 inches from the zero line , e . g ., bottom line of the supported x - ray film 18 . the device 10 , if desired , may include a web 17 adapted to carry a plurality of vertically spaced rows e . g ., decks 18 and 18 a of x - ray films . while the device 10 is shown with two decks 18 and 18 a , the device 10 may have a single deck or there may be more than two decks . the sensor 26 c may be placed at a location to sense the leading edge and the trailing edge of the upper row of x - ray films 18 a . the sensor 26 d is placed slightly more than 10 inches from the zero line of the upper row of x - ray film 18 a on the web 17 . the reading station 14 ( fig2 and 3 ) may include a sheet of thick etched polymer 15 . the polymer sheet 15 serves to support the composite of web 17 and x - ray film sheets 18 . the polymer sheet 15 may be supported by the frame 11 in a position that provides proper orientation for the reading of the x - ray film 18 by the doctor or radiologist . a lighting bank 29 is disposed to the rear of the polymer sheet 15 to illuminate the x - ray film sheet 18 at the reading station 14 . the lighting bank 29 includes a plurality of sets of lamps , such as lamps 31 , 32 . the lamp set 31 is adapted to illuminate x - ray film 18 that is the shortest set , e . g ., 10 inches in vertical dimension . the light set 32 is adapted to illuminate , in combination with light set 31 , the x - ray film sheets 18 that are 12 inches in vertical dimension . light set 31 includes a plurality of vertically oriented lamps 31 a - 31 h . the lamps 31 a - 31 h may be identical in construction and includes a reflector support 36 in which a lamp 37 is supported . the reflector support 36 may be channel shaped as shown in fig4 . the lamp 37 may be a string lamp of the type available from jkl lamps , inc . of california under the designation ccfc ( cold cathode flourescent ). the lamps are of the type used in lap top computer screens . typically such lights or lamps will be 3 mm in diameter and may be of any desired length the combination of the support 36 and lamp 37 is mounted on a mother board 38 . the support 36 may be constructed of polymer and formed in the desired shape such as by vacuum molding . light set 32 may be similar in construction to light set 31 , however , light set 32 is only 2 inches in length and includes a plurality of vertically oriented lamps 32 a - 32 h . the lamps 32 a - 32 h may be identical in construction to the lamps 31 a - 31 h except for length . the lamps 32 a - 32 h are mounted on the mother board 38 as described with respect to lamps 31 a - 31 h . the second embodiment of the present controlled light source device 110 ( fig6 ) for reading x - ray film may include a frame 111 supporting a first roll support 112 , a second roll support 113 and an x - ray reading station 114 . the frame 111 may be of any suitable construction . the first roll support 112 is horizontally supported and is adapted to carry a horizontal roll 116 of a composite of web 117 and a plurality of sheets of x - ray film 118 . the web 117 may be of any suitable transparent polymer sheet material having sufficient strength and integrity to carry and transport the x - ray film 118 . any suitable mechanism may be used to hold the x - ray films adjacent the web . for example , a trough 117 a may extend along one edge of the web / x - ray composite 117 / 118 . the second preferred embodiment 110 of the present invention thus may be similar in construction to the first embodiment 10 except the orientation of the rolls 112 , 113 and web 117 are for vertical movement of the web in contrast to the horizontal movement in the first embodiment 10 . the first roll support 112 may be in the form of a shaft 119 driven by an electric motor 121 . the roll 116 of the web 117 may be mounted for use by placement over the driven shaft 119 . the shaft 119 may be controlled by the small electric motor 121 to either permit controlled stripping of the composite 117 / 118 from the roll 116 or to provide powered wrapping of the composite 117 / 118 onto the roll 116 . the second roll support 113 may be in the form of a shaft 122 driven by an electric motor 124 to support the second roll 123 of the web 117 . the shaft 122 serves during normal operation as to strip the composite of web 117 and x - ray film sheets 118 from roll 116 and wrap the composite 117 / 118 onto roll 123 . the operation of power driven shafts 119 and 122 may be reversed so that the composite of web 117 and x - ray film sheets 118 are stripped from roll 123 and wrapped onto roll 116 . this permits the doctor or radiologist to again study an x - ray film that has already passed the reading station 114 by return of the x - ray film to the reading station . the device 110 includes sensing mechanism 126 that serves to scan the composite of the web 117 and x - ray film 118 . the sensing mechanism 126 is a strip sensor and may include a plurality of individual sensors forming the elongated strip that senses the entire length and breadth of the x - ray film 118 . the sensing mechanism 126 is disposed downstream of the roll 116 and upstream of the reading station 114 . the sensing mechanism 126 may be a plurality of photoelectric cells operated on any of various principles such as reflective light or a system in which the amount of light passing through the composite 117 / 118 is measured . suitable photoelectric cells or sensors 126 are described in u . s . pat . nos . 4 , 356 , 393 and 5 , 808 , 256 . the individual sensors 126 may be positioned to read the presence of the x - ray film in the path leading from the roll 116 to the reading station 114 . the sensor 126 may be placed in a location to read the leading edge of the x - ray film and the trailing edge of the x - ray film along with film height . the sensor 126 a compiles data defining where an x - ray film 118 begins and ends in the supported position on the web 117 . the device 110 , if desired , may include a web 117 adapted to carry a plurality of spaced decks of x - ray films 118 and 118 a . while the device 110 is shown with two decks , the device 110 may have a single deck 118 or there may be more than two decks . the sensor 126 c may be placed at a location to sense the leading edge 118 ′ and the trailing edge 118 ″ of the upper row of x - ray films 118 a . the reading station 114 may include a sheet of thick etched polymer 115 . the polymer sheet 115 forms a path that serves to support the composite of web 117 and x - ray film sheets 118 . the polymer sheet 115 may be supported by the frame 111 in a position that provides proper orientation for the reading of the x - ray film 118 by the doctor or radiologist . a lighting bank 129 is disposed to the rear of the polymer sheet 115 to illuminate the x - ray film sheet 118 at the reading station 114 . the lighting bank 129 includes a plurality of sets of lamps , such as lamps 131 , 132 . the light set 131 is adapted to illuminate x - ray film 118 that is the shortest set , e . g ., 10 inches in vertical dimension . the light set 132 is adapted to illuminate , in combination with light set 131 , the x - ray film sheets 118 that are , for example , 12 inches in vertical dimension . light set 131 includes a plurality of vertically oriented lamps 131 a - 131 h . the lamps 131 a - 131 h may be identical in construction and includes a reflector support 136 in which a lamp 137 is supported . the reflector support 136 may be channel shaped as shown in fig4 . the lamp 137 may be a string lamp or light of the type available from jkl lamps , inc . of california under the designation ccfc ( cold cathode flourescent ). support 136 and lamp 137 is mounted on a mother board 138 . the support 136 may be constructed of polymer such as by vacuum molding . lamp set 132 may be similar in construction to light set 131 , however , light set 132 is only 2 inches in length and includes a plurality of vertically oriented lamps 132 a - 132 h . the lamps 132 a - 132 h may be identical in construction to the lamps 131 a - 131 h except for length . the lamps 132 a - 132 h are mounted on the mother board 138 as described with respect to lamps 131 a - 131 h . various modifications can be made to the device 110 , for example , the elongated film 117 may be adapted to carry more than two rows of x - ray films . further , the device 110 may be adapted to carry over sized sheets of x - ray film that may over lie the two rows of the web .