METHOD OF TRANSFERRING PHOTOSENSITIVE MATERIAL AND APPARATUS THEREFOR

Abstract: A method or transferring a strip-form photosensitive material comprising mounting a feed roller on an upstream side and a transferring roller on the downstream side with an exposure table located therebetween and intermittently transferring the photosensitive material onto the exposure table only in the predetermined feed size, characterized by measuring in advance a feed size of the paper based on number of revolution of the feed roller and a feed size of the paper based on number of revolution of the transferring roller and compensating for the number of revolution given to both rollers in order to prevent an error generated between both paper feed sizes. It is possible to accurately transfer the same size as that after the paper is sandwitched between the transferring roller even when the paper head end is not yet sandwitched between the transferring roller and is sent out only by the feed roller, because the paper feed size based on the number of revolution of the feed roller is controlled to be the same as the paper feed size based on the number of revolution of the transferring roller.

Description: TECHNICAL FIELD The present invention relates to a method of transferring photosensitive material and apparatus used therefor. More particularly, it relates to a method of transferring a strip-form photosensitive material (hereinafter called "paper") and an apparatus used therefor which can transfer the paper in such a manner to prevent a difference between the predetermined feed size, in particular, when the paper head end portion is sent out only by feed rollers (the size is a print size corresponding to one image which is intermittently sent by a transferring device, and for example, if the film has mixed images of varying print sizes such as full size or panorama size, each adequate a predetermined length of the paper corresponding to the relevant one image which is sent out), and the feed size when the paper head end portion is transferred with being sandwiched between transferring rollers and with back tension being given between the transferring rollers and the feed rollers. BACKGROUND ART Fig. 8 shows one example of a photo-processing apparatus. This photo-processing apparatus comprises a printing part 1 for printing images on the paper and a processing part 2 for carrying out treatments of the printed paper, such as a development. To the printing part 1, there are equipped along the paper transferring route a loading part 3 for transferring the paper to the exposure table, an exposure table 4 for printing and exposing, an advance part 5 for accurately transferring a predetermined length of the paper, a paper transferring part 6 and a stock tank part 7 which can form loops for adjusting the advance of the paper to be sent out to the processor part 2, and an outlet part 8. In the processing part 2, there are provided a processor rack part 9 in the treatment tanks for carrying out color development, bleaching, and fix stabilization, a dryer part 10 in a drying tank for drying the paper, and a cutter part 11 in the vicinity of the outlet, respectively. In such photo-processing apparatus, a paper-transferring apparatus is installed for transferring the paper by means of a plurality of rollers from the process of pulling out a proper amount of paper wrapped and held around a roll magazine (not shown) in a roll form, until the process of printing at an exposure stand 4 and the process of finishing the paper into a print at the processing part 2. As shown in Fig. 1, particularly, the paper P sent out onto the exposure stand 4 must be transferred exactly by one print size (a predetermined feed size referred to in the claim) in view of the fact that an image is printed on it. Therefore, in Fig. 1, the feed roller 22 mounted on the upstream side of the exposure stand 4 and the transferring roller 23 on the downstream side on the transferring route of paper P are both connected to a pulse motor, and are given precisely the same number of revolutions so that the feed size can be controlled with back tension given to the paper. However, as shown in Fig. 1 (a), the feed size of the paper P is controlled based on the number of revolutions of the feed roller 22 until the head end P1 of the paper P is sandwiched between transferring rollers 23, and as shown in (b) of Fig. 1, the feed size after the paper is sandwiched between transferring rollers 23 is controlled based on the number of revolution of transferring rollers 23. Consequently, controlling the number of revolutions of both rollers in the same manner gives rise to the problem that the paper is unable to be transferred exactly in the predetermined size if there is any error in the outside diameters of both rollers. The difference of the outside diameters of both rollers is caused not only by processing problems but also by the fact that the outside diameter of the feed roller 22 is intentionally made smaller than that of the transferring roller 23 in order to provide back tension to the paper after it is held between the transferring rollers. In the latter case, in particular, there are problems of various inconveniences such as a positional discrepancy of the image in the finished print or a deviation of the cut size because the dimensional deviation becomes remarkable. There is also the problem of generating waste at the paper head end portion if the paper is exposed after the head end of the paper is held between the transferring rollers. In addition, there can be assumed a case in which the number of revolutions of the feed roller and that of the transferring roller are individually set in advance to feed the predetermined size because of the difference in the outside diameters between the feed roller and the transferring roller. There is, however, a case in which the paper is sandwiched between the transferring rollers before the predetermined size is completely sent out with the feed roller only. In such case, the predetermined size is unable to be sent out unless special countormeasures are taken. In addition, in the above-mentioned photo-processing apparatus, in general, a plurality of driving rollers are used and between respective driving rollers, a difference is generated in the roller outside diameters due to processing errors, driving motor control method differencies, or roller material differencies, thereby generating a difference in the feed rate of each driving roller. Consequently, in order to absorb the error of the feed rate of each driving roller, there have been a method of measuring the feed rate per one rotation of each driving roller, comparing the measured value with the theoretical value, increasing or decreasing the feed rate based on the comparison results, and compensating the error, and a method of providing a buffer to absorb the error (for example, a method of intentionally slacking the paper and pulling it out when more than a predetermined slack volume is formed). However, even if the error is compensated for individual rollers, there is the problem that it is extremely difficult to completely synchronize all the rollers, and there is the other problem that even if a buffer is provided, an apparatus for controlling the buffer is required and thus more costs or space are required. Under the foregoing circumstances, it is an object of the present invention to provide a method of transferring a paper and apparatus used therefor which can constantly provide the predetermined feed size whichever feed roller or transferring roller is driven with a different outside diameter. Still another object of the present invention is to provide an apparatus of transferring photosensitive material which can apply proper tension to the paper so that the paper traveling condition is good, and which can absorb the error of the feed rate caused by the processing error of the roller outside diameter so that strict roller processing accuracy is not required but cost reduction can be achieved The paper-transferring method according to the present invention comprises a roller on the upstream side of said apparatus and a transferring roller on the downstream side of said apparatus with an exposure table located therebetween, wherein the photosensitive material is intermittently transferred onto the exposure table only in a predetermined feed size, characterized by first measuring in advance a feed size of the photosensitive material based on the number of revolutions of the feed roller until the head end of the photosensitive material is sandwiched between the transferring roller and then a feed size of the photosensitive material based on the number of revolutions of the transferring roller, and compensating the numbers of revolutions given to both rollers in order to prevent an error generated between both measured feed sizes. The photo-processing apparatus adapted for carrying out the method of the invention comprises a feed roller mounted on the upstream side of said apparatus and a transferring roller on the downstream side of said apparatus with an exposure table located therebetween, characterized by a control mechanism for controlling the numbers of revolutions of the feed roller and the transferring roller in order to intermittently transferring a strip-form photosensitive material onto the exposure table only by a predetermined size. According to a particular embodiment of the method of the invention, the method is characterized by controlling the predetermined feed size based on the number of revolutions of the feed roller until a paper head end of the photosensitive material is sandwiched at the transferring roller and controlling the predetermined feed size based on the number of revolutions of the transferring roller after the photosensitive material is sandwiched at the transferring roller, and, if the predetermined size of the photosensitive material can not be sent out by the feed roller and is to be sandwiched at the transferring roller, stopping the rotation of the feed roller just before the photosensitive material is sandwiched at the transferring roller, computing the size short for the predetermined feed size by computing the feed size which the feed roller has sent, computing the number of revolutions of the transferring roller corresponding to the computed value, and rotating the transferring roller in line with the computed value. In the method of the present invention and the apparatus used therefor, the feed size of the paper based on the number of revolution of the feeding roller is controlled to achieve the same paper feed size based on the number of revolution of the transferring roller by measuring and compensation. Therefore, the predetermined feed size same as that after the paper is sandwitched between transferring rollers can be accurately transferred when the paper is sent out only by the feed roller before the paper head end is sandwitched between the transferring roller. Further, the numbers of revolution of the feed roller and the transferring roller are independently set in advance to send the predetermined feed size, and when the paper is sandwitched between the transferring roller before the predetermined feed size have been sent out, the number of revolution equivalent to that short for the predetermined feed size is given to the transferring roller to send the predetermined feed size. The capability of the feed rate of each driving roller can be adjusted by providing a difference in the outside diameter of each driving roller or by providing a difference in the number of revolution of each driving roller. It is also possible to easily cause the paper to slip on the outer circumferential surface of the roller by forming the driving roller with the material with a small frictional coefficient. The driving roller mounted at the position in contact with the emulsion surface of the paper can be slipped without rubbing the paper surface by installing a torque limiter in such a manner that the driving roller is allowed to slip at the driving source. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an operational explanatory view of one embodiment of a paper-transferring apparatus according to the invention; Fig. 2 and Fig. 3 are explanatory views showing a compensation method of the paper-transferring apparatus of the invention; Fig. 4 is an explanatory view of another embodiment of the paper-transferring apparatus according to the invention; Fig. 5 is an explanatory view showing one example of construction of a photo-processing apparatus. BEST MODE FOR CARRYING OUT THE INVENTION Referring now to the drawings, the paper-transferring method of the present invention and the apparatus used therefor will be described in detail hereinafter. Fig. 1 is an operational explanatory view of one embodiment of the paper-transferring apparatus according to the invention. In (a) of Fig. 1, paper P is sent out onto an exposure table 4 with a paper mask 21 being closed, and a head end P1 is transferred with being sandwitched between the exposure table 4 and the paper mask 21. Keeping the paper mask 21 closed until the paper head end P1 reaches the transferring roller 23 can prevent the paper P from being slackened. A feed roller 22 and the transferring roller 23 are driven by motors such as pulse motors which can provide accurate numbers of revolution. For example, in the case of the pulse motor, by controlling the number of pulses given, an accurate number of revolutions can be given. Because the transferring apparatus according to the present invention must send exactly one print size intermittently onto the exposure table 4, this kind of pulse motor or the like are used. As shown in (a) of Fig. 1, because the paper is sent out only by the feed roller 22 until the paper head end P1 is sandwitched between the transferring roller 23, the feed size is controlled by the number of revolutions of the feed roller 2 2. Because, after the paper head end is sandwitched between the transferring roller 23, the transferring roller 23 pulls the paper and the feed roller 22 slips to provide tension to the paper, the feed size being controlled by the number of revolutions of the transferring roller 23. The present invention is designed to correct the feed size of the feed roller 22 and the feed size of the transferring roller to be constant even when the outside diameters of the feed roller 22 and the transferring roller 23 differ from each other, and the correction is carried out by measuring the actual feed sizes of the feed roller and the transferring roller. The difference of the outside diameters include manufacturing errors in addition to a planned design difference. Referring now to Figs. 2 to 3, one example of measuring and correction is described. First of all, as shown in Fig. 2, the correction of the feed size of the paper head end sent out only by the feed roller 22 to be constant is carried out by providing in advance marks M1, M2 (for example, small holes) for indicating a constant length L for reference on the side face or on the upper surface of the exposure table 4 and by giving the feed roller 22 the number of revolutions for sending the paper only by the length L estimated from the outside diameter of the feed roller 22. Based on whether the paper reaches the distance L as predicted, the number of revolutions is increased or decreased to determine the number of revolutions which can feed exactly the reference length L. If a pulse motor is used, the number of pulses is determined. The comparison with the above-mentioned reference length L is carried out by measuring the interval of the punch holes drilled by a punch unit 24. That is, as shown in Fig. 3, the head end portion A of paper P is the portion sent out only by the feed roller 22. The number of revolutions (or the number of pulses) is adjusted so that the interval of the punch holes located at this section A becomes the reference distance L. Then, correction of the feed size after the paper is sandwitched between the transferring roller 23 is carried out by measuring the interval of punch holes formed at section B which is not subject to the influence of the feed roller 23 as shown in Fig. 3. If this interval N is compared and is found to be smaller than the reference length L, positive correction is carried out, and if it is larger than the reference length L, negative correction is carried out. Further, as described above, if the predetermined size is unable to be sent only by the feed roller 22 even with both corrected rollers 22, 23, that is, if the paper of one print size length is unable to be sent and is sandwitched between the transferring roller 23, the remainder size must be transferred by the transferring roller 23. For example, if the print width to be printed in the exposure area E is F, as shown in (a) of Fig. 4, the feed roller 22 and the transferring roller 23 must intermittently send the paper exactly as much as the print size F. Because the paper head end P1 is sent by the feed roller 22 until it is sandwitched between the transferring roller 23 at the point A, this print size F is controlled by the number of revolutions of the feed roller. However, if only the size L1 is sent to the exposure area E when the paper head end P1 reaches the point C, the remainder size L2 must be sent by the transferring roller 23. Therefore, in such event, how much the transferring roller 23 must be rotated additionally is computed as follows. First of all, in (a) of Fig. 4, the feed roller 22 is temporarily stopped when the paper head end P1 reaches the point A. Then, how much the roller has been rotated to this point after the feed roller 22 finishes sending the print size of one print before is measured. This measurement is carried out by determining the number of pulses given to the motor before this point if the control mechanism uses a pulse motor, and the feed size L1 which the feed roller 22 has sent is computed from the number of revolutions of the feed roller 22. The remainding size L2 is computed by the following formula, namely L2 (remainder size) = F (print size) - L2 (feed size of the feed roller). Then, let the size which the transferring roller 23 can feed in one rotation be S, the number of revolutions of the transferring roller 23 required for sending the remainding size L2 is expressed by Number of revolutions of the transferring roller 23 = L2/S. As described above, even when one print size is delivered from the feed roller 22 to the transferring roller 23 on the halfway of feeding one print size, it is possible to send exactly one print size. Referring now to one pulse as an example, this is discussed more specifically, because the number of revolutions is proportional to the number of pulses when both rollers 22, 23 are driven by a pulse motor. For example, assume that if the paper head end P1 is sent only by the feed roller 22, giving one pulse to the feed roller 22 sends the paper 1 mm. On the other hand, after the head end P1 is sandwitched between the transferring roller 23, one pulse is given to both the transferring roller 24 and the feed roller 22, and assume that the feed rate of the paper in this event is 1.5 mm. Now, let the print size F of the print to be printed be 100 mm and the number of pulses given to the feed roller 22 be P1 when the paper head end reaches the point A, the number of pulses P2 to be given to the transferring roller 23 is found by P2 = (100 - 1 × Pl)/1.5. As described above, the method of transferring the paper and the apparatus used therefor according to the invention is able to accurately transfer the same size as that after the paper is sandwitched between the transferring roller even when the paper head end is not yet sandwitched between the transferring roller and is sent out only by the feed roller, because the paper feed size based on the number of revolutions of the feed roller is controlled to be the same as the paper feed size based on the number of revolutions of the transferring roller. This achieves remarkable effects particularly when there is a difference in the outside diameters between the feed roller and the transferring roller. The predetermined feed size which the transferring apparatus of the invention intends to intermittently send is, for example, one print size, and even when the head end of the paper is delivered from the feed roller to the transferring roller in the midst of feeding one print size, the remaining feed size is computed from the feed size of the feed roller and the remaining feed size is controlled to be sent by the transferring roller, and it is possible to constantly maintain the predetermined feed size. Consequently, even the portion before the paper head end which is sandwitched between the transferring roller can be used for printing in the same manner as the portion after that which is sandwitched by the transferring roller; the loss of the portion can be eliminated and at the same time, the positional deviation of the image in the finished print or deviation of the cut size can also be eliminated. Using a torque limiter for the driving roller in contact with the emulsion surface to allow the driving roller to slip at the driving source and to prevent slip on the roller surface can prevent detrimental effects on the photo quality. INDUSTRIAL APPLICABILITY The method of transferring the paper and the apparatus used therefor according to the present invention can accurately transfer the paper exactly as much as the predetermined size and are very useful, in particular, for the photo-processing apparatus equipped with a paper-transferring mechanism.

Claims: A method of transferring a strip-form photosensitive material in a photo-processing apparatus comprising a feed roller on the upstream side of said apparatus and a transferring roller on the downstream side of said apparatus with an exposure table located therebetween, wherein the photosensitive material is intermittently transferred onto the exposure table only in a predetermined feed size, characterized by first measuring in advance a feed size of the photosensitive material based on the number of revolutions of the feed roller until the head end of the photosensitive material is sandwiched between the transferring roller and then a feed size of the photosensitive material based on the number of revolutions of the transferring roller, and compensating the numbers of revolutions given to both rollers in order to prevent an error generated between both measured feed sizes. The method according to claim 1, characterized by controlling the predetermined feed size based on the number of revolutions of the feed roller until a paper head end of the photosensitive material is sandwiched at the transferring roller and controlling the predetermined feed size based on the number of revolutions of the transferring roller after the photosensitive material is sandwiched at the transferring roller, and, if the predetermined size of the photosensitive material can not be sent out by the feed roller and is to be sandwiched at the transferring roller, stopping the rotation of the feed roller just before the photosensitive material is sandwiched at the transferring roller, computing the size short for the predetermined feed size by computing the feed size which the feed roller has sent, computing the number of revolutions of the transferring roller corresponding to the computed value, and rotating the transferring roller in line with the computed value. A photo-processing apparatus adapted for carrying out the method of claim 1 or 2, comprising a feed roller (22) mounted on the upstream side of said apparatus and a transferring roller (23) on the downstream side of said apparatus with an exposure table (4) located therebetween, characterized by a control mechanism for controlling the numbers of revolutions of the feed roller (22) and the transferring roller (23) in order to intermittently transferring a strip-form photosensitive material (P) onto the exposure table (4) only by a predetermined size.

Inventors: NARUKAMI SHINJI, NARUKAMI, SHINJI
Applicants: NORITSU KOKI CO LTD, NORITSU KOKI CO., LTD.
Application year: 1995
Main classification: G03B1
IPC codes: G03B27