GB2031174A - Projection printing - Google Patents

Abstract

A projection printer comprises illumination source 101, holder 11 for transparent original 110, lens turret 12 having means 121/122 and 48/26 for adjusting and sensing its longitudinal and angular positions, holder 13 for photosensitive film having means 138/ 139 for adjusting and sensing its longitudinal position, masks 14 having means 301/302 for adjusting and sensing their lateral positions, and memory and control means 22 by which the variables may be set, manually or automatically, for a desired image format and given original format. <IMAGE>

Description

SPECIFICATION Copying device The present invention relates to a copying devicewhich is suitable especially for a largely automated production of photographic enlargements of originals, especially of diapositives by transillumination.

For the production of photographic enlargements of coloured negatives in technical or industrial operation, various copying devices are known which make possible a largely automated operation, but which permit little or no degree of freedom in respect of the size of the original and the image. With the considerable standardisation of negativeformats and the limited number of image formats that are normally desired of the enlarged copies, this does not however constitute any serious disadvantage.

A method forthe production of coloured viewing copies from viewing originals and a device suitable for same are described in Swiss Patent Specification 570,632 of the Applicant and make possible an economic solution to the problems associated with the production of viewing copies, e.g., from instant cameras, on a technical scale. In this known method, a commercially obtainable copying material -- a so-called reverse paper -- is used, which permits the production of coloured copies by direct projection of a coloured viewing original, that is a positive image, for example, by means of an episcope optic onto the paper, without the use of an intermediate negative.

The production of enlarged coloured copies of coloured diapositives is a further problem of commercial copying centres, which in essence could be solved in a simplified manner with the aforementioned reversing paper, but for which however no devices are hitherto available which make possible largely automated operation and thereby provide considerable degree of freedom in respect of the differing formats of the original and the copies.

The problem underlying the present invention therefore is to provide a copying device, which is suitable especially for largely automated production oftransilluminated enlargements of differing formats, for example from 9 x 13 cm to 30 x 45 cm, directly from diapositives which likewise are of widely varying formats for example from 13 x 17 mm to 6 x 7 cm, with a minimum of conversion work and wastage of paper.

In order, for example, to enlarge twenty different formats of an original or diapositive to the eight widths of paper necessary for the above-mentioned range of enlargement formats, enlargement scales from about 1:1.9 to 1:25, and therefore a plurality, for example four, object lenses are necessary with different focal lengths and corresponding changes in the distances between the selected object lens and the original on the one hand and the chosen object lens and the image tray on the other hand and also of the screening mask.

According to the present invention there is provided a copying device suitable for the production on reversing. paper of coloured enlargements of differing formats from coloured diapositives of differing formats comprising an illuminating device, an original holder, an object lens support carrying a plurality of focal lenses of different focal lengths, an image tray including a multi-part mask having two edge battens displaceable relative to each other to define the mask aperture, the object lens support.

and the image tray being independently displaceable relative to the original holder storage means for storing data representing the set-point values necessary for defined copying scales of the object lens focal length, the distance between the object lens support and the original holder, the distance between the image tray and the original holder, and the dimensions of the corresponding aperture of the mask and means operable to'correspondingly adjust said distances and dimensions in correspondence with the data representing the set-point values for a selected copying scale.

The copying device according to this invention possesses an illuminating device, an original holder an object lens support and also an image tray with a multi-part mask and is characterised in that forthe production of images of differing formats from originals also of differing formats, a plurality of object lenses possessing different focal lengths are disposed upon the object lens support and the object lens support and also the image tray are displaceable independently of each other and relative to the original holder, and that at least two edge battens of the mask are displaceable relative to each other, the device possessing, to enable it to be adjusted in a reproducible manner, means for storing at least the set-point values, required for defined copying scales, of the object lens focal length, of the distances between the object lens support or image tray and the original holder and of the corresponding aperture of the mask, and also means for adjusting said actuating variables in agreement with the stored set-points.

Embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings in which: Figure 1 is a diagrammatic view of a copying device according to the invention, Figure 2 is a diagrammatic view of an object lens support for the device of Figure 1.

Figure 3 is a diagrammatic view of an example of storage and adjustment means for the actuating variables of the copying device of Figure 1 and Figure 4 is a diagram showing the selection of object lens with an object lens support according to Figure 2.

The copying device 1, illustrated diagrammatically in Figure 1, is illustrated with its principal components, but without mechanical, electrical and optical auxiliary equipmentfor the sake of simplicity. It comprises an illuminating device 10 comprising a light source 101, for example a halogen lamp with a mirror (not shown) a condensoroptic 102, for example an aspherical condensorfor projecting the spiral image to infinity, and a filtering device 103 for filtering out infrared and ultraviolet radiation.Preferably, the light is conducted via a diffusion chamber (not shown) of known type and via a filtering system (not shown) for regulating the colour of the copying light which filter system may comprise a plurality of pivotal, subtractive copying filters of varying densi ty,which can be used in known mannerwhen required with a control system (not shown) preferably via a suitable memory with a keyboard.

An equipment support portable 9 formed with an appropriate light transmitting passage carries a holder 11 for the original to be copied, for example, a diapositive 110. For using differing original formats, correspondingly adapted guide frames may be employed. For compensation purposes, for instance when using diapositives covered with glass, a monitored displaceability of the original holder in the vertical direction by a few millimetres may be advisable. Furthermore, a horizontal adjustment device and/or a blanking frame (not shown) for covering the top of parts of the diapostive 110 may be used and may be connected to the original holder 11.

An object lens support 12 which is displaceable vertically in the direction of double arrow A contains a plurality, for example four, of object lenses of which the lenses 15, 15', 15" are shown. These lenses have different focal lengths, for example 28, 50, 80 and 100 mm. In order to rotate one of the object lenses 15 into the optical axis C of the device 1, the object lens support 12 includes a rotatable disc 17, in which the object lenses are mounted at 900 intervals about the axis of rotation thereof (Figure 2). Preferred means 18 for the opto-electronic control of the rotation of a specific object lens are described below.

In the simplest case, the disc 17 may be rotated by a motor 48 and be moved by mechanical-electric means to the desired angular position and fixed in this position. The actual object lens in the operative position can be indicated by a device 22 of the control desk.

The distance of the object lens support 12 from the original holder 11 is determined by its position on an associated guide spindle 32. This position can be varied by actuating a motor 121 and may be monitored by an opto-electronic angle position sensor 122 which is operative to provide an indication of the actual value of this distance. The setting of the object lens support 12 to the distance required for a desired focal length of object lens is explained in more detail below.

An image tray 13 is spaced along the optical axis from the lens support 12 and includes an opaque housing 130 containing two cassettes 131, 132 which are preferably removable, for the unilluminated and illuminated reversing paper 133 which extends between the cassettes. In the image tray 13 there is a guide spindle 30, on which the parts 14, 14' of an image or covering mask can be guided in opposite directions to each other. The guide spindle 30 is rotatable by a motor 301 and its actual or instantaneous position can be monitored by an optoelectronic angle position sensor 302. Further details of the device (not shown) for conveying the paper and actuating closure 135 can be obtained from the aforementioned Swiss Patent Specification No.

570,632, it being only pointed out here that the image tray 13 is with advantage constructed to enable various widths of paper to be used, for example papers having widths of 127, 178,203,254, 280 and 305 mm.

The image tray 13 is displaceable relative to the original holder 11 in the directions of the double arrow B and is connected to a guide spindle 31. The position of the image tray 13 on the guide spindle 31 can be varied by actuating a motor 138 and can be monitored by the opto-electronic angle position sensor 139.

The device 1 possesses a control desk 20 which may contain storage or memory means 25 or may be connected to a separate store or memory. It possesses furthermore first devices 21 for inputting the set-point values or desired values and second devices 22 for indicating the actual or instantaneous values and the control deviations of the actuating variables. It will be understood that the device normally possesses a control desk (not shown) either combined with control desk 20 or separate therefrom, for inputting starting signals, stopping signals, colour-correcting and density-correcting values and for other possible correction values, for example for correcting the focus when diapositives covered with (lass are used, and which is connected to correspons ng memories for the operating values.

Suitable devices are known and will be readily understood by the skilled person and therefore do not require any further explanation here.

In the description below, therefore, the means used for reproducibly adjusting the device, for storing the setpoint values required for defined copying scales of the objective lens focal length (choice of objective lens 15) for the distances of the objective lens support 12 or image tray 13 from the original holder 11 and forth corresponding aperture of the mask components 14, 14' and also the means for setting said actuating variables in agreement with the stored set-point values are explained.

A first example of a storage or memory means for the set-point values of a defined, i.e., predetermined copying scale, is an interchangeable card 25 visible on the control desk 20 and possessing readable symbols. These symbols can be read off by the operator and used for actuating the device 21. The agreement of the set-point values of the card 25 with the actual values illustrated in the device 22 can also be checked or established by the operator.

A second example of a storage or memory means for the set-point values of the actuating variables for a defined copying scale is a data carrier readable by a machine and of conventional type. In this case a -w conventional reading device is associated with or after the control desk and calls up the stored data from the data carrier and transmits them as reference inputs to the corresponding control and/or regulating circuits.

A third example of a storage or memory means for the actuating variables of this invention is an electronic memory of conventional type, in which case the control desk contains corresponding devices for input storage, reading out and deleting of the stored set-point values. The values read out from the electronic memory are transmitted as reference inputs to the corresponding control and/or regulating circuits.

As mentioned above, in the device 1 illustrated in Figure 1, the object lens support 12, the image tray 13 and the parts 14,14' ofthe image mask are respectively coupled to motor-driven spindles 32,31 and 30 for independent displacement of each of these assemblies. The means for adjusting the set-point values of these assemblies are preferably generally constructed as electronic circuits, in particular as control circuits, as explained by the example in Figure 3. For each actuating variable, a set-point selector, formed for instance as a potentiometer 35, is provided on the control desk 202, with an associated actuator 36. By this actuator 36 the associated motor 37 (i.e., one of the motors 121, 138 or 301 of Figure 1) is connected to a supply voltage source 39 and moves the associated guide spindle 38 (i.e., the spindles 30,31, and 32 of Figure 1).The guide spindle 38 co-operates with an opto-electronic angle position sensor 41 which converts the analogue rotation of the associated guide spindle into a digital signal, which corresponds to the current or instantaneous distance of the object lens support 12 or image tray 13 from the original holder 11 or to the distance of the edges of the mask components 14, 14' from each other as the case may be and the corresponding value appears at the indicator 42.

According to a preferred form of embodiment, each opto-electronic angle position sensor 41 comprises two discs of which the first is connected with the associated guide spindle 38 in respect of movement. The second disc is connected in respect of movement via a reduction gear with the first disc.

The two discs are each rotatable between associated sets of photoelectric cells and carry numerals, disposed on concentric tracks, readable in the radial direction and coded, for instance, in BCD code, which numerals correspond to the current actual value of the control variable and are indicated in the second device 42 of control desk 202. Alternatively, a corresponding electronic comparator may be used, which compares the setpoint value from the memory with the actual value; the deviation can be used in known manner for control, if necessary together with a device which indicates only the coincidence of set-point value and actual value or lack of coincidence and which may be automatically blocking.

As mentioned above, the positon of the rotatable disc 17 of the object lens support 12 is preferably likewise opto-electronically monitored and regulated. An example is shown in Figure 4. The opto-electronic means 18 serve for producing a binary coded signal corresponding to the angular position of the disc and are part of a control circuit, which possesses a set-point sensor 45, disposed on the control desk 203, constituted as a step switch and producing a binary coded signal. The two binary coded signals are transmitted to the inputs of a set-point/actual value comparator 46 and a control signal appears at the output of the comparator 46 for the actuator 47, which connects the drive motor 48 for rotatable disc 17 to a supply voltage U until the actual value signal corresponds to the set-point value signal.

According to a preferred form of embodiment, the opto-electronic means 18 of the control circuit for the selection of the object lens contains a plurality of photo-electric cells, for example four, disposed alongside or above one another, one specific shaped object 26 being associated with each object lens 15, 15'15" etc., which shaped object interrupts one or more photoelectric cells and thereby produces a signal which corresponds to the number, coded for instance in BCD code, of the object lens rotated at that time into the optical axis C of the device 1.

For practical operation of the device 1 for the production of coloured enlargements in the range of the aforementioned scales and formats using object lenses of the stated focal lengths, the distance between the image tray (the reference point is the centre of the portion of paper situated between mask components 14, 14') and the original holder (diapositive) can be varied between 400 and 900 mm, and the distance between the object lens support (the reference point is the common optical plane of the object lenses) and the original holder (diapositive) can be varied between 20 and 220 mm. The distance between the edge portions of the mask components can be varied between 70 and 500 mm. A reproducibility of the set vaues of + 0.1 mm is here achievable and sufficient.The values provided in a memory of the device for the paper widths, the diapositive formats and the choice of upright format/broadsheet format can be called up and introduced by actuating appropriate keys. The systems required for electricity supply, lamp cooling, electronic control and the like can be housed in the lower part of the device.

Suitable auxiliary equipment for measuring the illumination, controlling the illumination and transporting the paper as a function of the mask position are described in the aforementioned Swiss Patent Specification No. 570,632. As examples of a suitable filter system for colour control of the copying light, a basic filtering system consisting of three groups (for yellow, purple and blue-green) each comprising five rotatable magnets with filter blinkers mounted thereon with values of 0.05, 0.1, 0.2, 0.4 and 0.8, together with a correction system consisting of three groups of four rotatable magnets each with filter blinkers mounted thereon with values of 0.05, 0.1, 0.2 and 0.4 may be mentioned.The basic filtering may with advantage be controlled from an electronic memory and the filter combinations required in each case (and basic illumination sensitivity) may be called up actuating a paper selection key.

The correction filters are with advantage controlled directly via a complete keyboard, for example comprising 9-11 keys for each of the three basic colours. This keyboard can also contain the density corrections. Density control can be carried out electronically by measuring the integral density of the diapositive original, comparing this measure mentwith the light sensitivity of the paper and determining an exposure time which leads to an image of standard density.

Since the functioning of the exposure meter can be influenced by basic sensitivity, scale correction, contrast and object lens defect correction, it is advisable to store the basic sensitivity for each paper separately and to call it up with the paper selection key. For scale correction, it is advisable for each of the various image configurations provided in the store (e.g. 240) to contain a corresponding factor (x99 to +99). The contrast (log density of original/ exposure time) requires correction only for diapositives which are deliberately under or over exposed, sine normal false exposures are compensated by the exposure meter; this correction can be achieved by changing the density/time function of the exposure meter. The object lens error correction (compensation of incorrect readings caused by in-integral measurement) is preferably carried out via a key board possessing, for example, ten keys from -4 through zero to +4.

Measurement of exposure itself is with advantage carried out by the light passing through the object lens being diffusely reflected from the matt white lower face of the closure cap and conducted to four concentrically disposed photoelements. Athreefigure correction value is with advantage used as scale correction for the exposure meter.

The device according to this invention is especially suitable for the production of coloured enlargements of diapositive, but is not limited to this application, nortotransilluminated originals.

Claims (16)

1. A copying device suitable for the production of reversing paper of coloured enlargements of differing formats from coloured diapositives of differing formats comprising an illuminating device, an original holder, an object lens support carrying a plurality of focal lenses of different focal lengths, an image tray including a multipart mask having two edge battens displaceable relative to each other to define the mask aperture, the object lens support and the image tray being independently displaceable relative to the original holder storage means for storing data representing the set-point values necessary for defined copying scales of the object lens focal length, the distance between the object lens support and the original holder, the distance between the image tray and the original holder and the dimensions of the corresponding aperture of the mask and means operable to correspondingly adjust said distances and dimensions in correspondence with the data representing the set-point values for a selected copying scale.

2. A device according to Claim 1 in which the object lens support includes a rotatable disc in which the object lenses are mounted angularly displaced about the axis of rotation thereof, control means is provided operable to generate a first binary coded signal representing the angular displacement of the disc about its axis of rotation corresponding to the angular displacement required to bring to the opera tive position an object lens of focal length corres ponding to the set-point value represented by the stored data for a defined copying scale, a position sensor is provided responsive to the angular posi tion of the disc to generate a corresponding second binary coded signal, comparison means is provided responsive to the difference between the first and second binary signals to generate an error signal and motor means is provided responsive to said error signal and operable angularly to displace the disc in the sense to reduce the error signal.

3. A device according to Claim 1 or 2 in which the object lens support and the image tray are mounted on separate spindles and are independently displaceable on said spindles by the means responsive to the corresponding set-point values to adjustthe distance thereof with respect to the original holder.

4. A device according to Claim 1,2 or 3 in which the mask aperture defining edge battens are relatively displaceable on a spindle by the means responsive to the corresponding set-point value.

5. A device according to Claims 3 and 4 in which the means responsive to the set-point values comprises a separate motor associated with each spindle.

6. A copying device, especially for the production of coloured enlargements of coloured diapositives on reversing paper, comprising an illuminating device, an original holder, an object lens support and an image tray comprising a multi-part mask, characterised in that, for the production of images of differing formats from originals likewise of differing format, a plurality of object lenses (15) of differing focal lengths are disposed on the object lens support (12), and that the object lens support (12) and also the image tray (13) are displaceable independently of each other relative to the original holder (11), and at least two edge battens of the mask (14,14') are displaceable relative to one another whereby the device possesses, to enable it to be adjusted in a reproducible manner, means for storing at least the set-point values necessary for defined copying scales, of the object lens focal length, of the distances ofthe object lens support (12) and image tray (13) from the original holder (11) and of the corresponding aperture of the mask (14,14') and also means for adjusting said actuating variables in agreement with the stored set-point values.

7. Device according to Claim 6, characterised by a control desk (20) with first devices (21) for inputting the set-point values and second devices (22) for indicating the actual values and control deviations of the actuating variables.

8. Device according to Claim 7 characterised in that the means for storing the set-point values of a defined copying scale are a replaceable card (25) possessing symbols which can be read by an operator and the first devices (21) are adjustment elements which can be actuated by an operator in agreement with the symbols on the card (25).

9. Device according to Claim 6 or7 characterised in that the means for storing the set-point values of a defined copying scale are a machine-readable data carrier and that a reading device is connected after the control desk, which reading device call up the stored data from the data carrier and transmits them as reference input to a control and/or regulating circuit.

10. Device according to Claims 6 or 7 characterised in that the means for storing the set-point values of a plurality of copying scales are an electronic memory and the control desk is provided for memory inputting, reading out and deleting of stored set-point values.

11. Device according to any one of Claims 6 to 10 characterised in that the object lens support (12) possesses a rotatable disc (17) on which a plurality of object lenses (15, 15',15") of differing focal lengths are disposed, that opto-electronic means (18) are provided which generate a binary coded signal corresponding to the angular position of the disc (17), that for the purpose of rotating an object lens (15,15',15") with a predetermined focal length into the optical axis of the device, a control circuit comprising a set-point emitter (45), constructed as a step switch, disposed on the control desk (203) and generating a binary coded signal, and (comprising) a set-point"actual value comparator (46) is provided, to the inputs of which the two aforementioned binary signals are transmitted and at the output of which a control signal appears for an actuator (47) which connects the drive motor (48) for the rotatable disc (17) to a supply voltage source until the actual value signal corresponds to the set-point signal.

12. Device according to any one of Claims 6 to 11 characterised in that there are associated with the object lens support (12), the image tray (13) and two mutually opposite parts (14,14') of the mask, a motor-driven guide spindle (30,31,32) for the displacement of each of these assemblies and that the means constructed as electronic circuits (Figure 3) for adjusting the set-point values for these assemblies are constructed as control circuits.

13. Device according to any one of Claims 6 to 12 characterised by set-point emitters, constructed for instance as potentiometers (35) and disposed on the control desk (202) to which are connected (on output side) actuators (36) which connect the associated drive motors (37) for the guide spindles (38) to a supply voltage source (39) whereby one optoelectronic angle position emitter (41) co-operates with eac of the guide spindles (38) which emitter converts the analogue rotation of the associated guide spindles (38) into a digital signal which corresponds to the current distance of the object lens support (12) or image tray (13) from the original holder (11) or to the distance between the two parts (14,14') of the mask and which is indicated in the second device (42).

14. Device according to Claim 11 characterised in that the opto-electronic means (18) contain photoelectric cells (25) disposed alongside or above one another and that there is associated with each object lens (15,15',15") of the object lens support (12) a specific shaped object (26) which interrupts one or more photoelectric cells and thereby generates a signal which corresponds to the number, coded for example in BCD code, of the object lens currently rotated into the optical axis of the device.

15. Device according to Claim 13 characterised in that the opto-electronic angle position emitter (41) contains two discs, of which the first disc is movingly coupled with the associated guide spindle (38) and the second disc is movingly coupled via a reduction gear with the first disc, and the discs are rotatable between associated sets of photoelectric cells, whereby the discs possess numbers, coded for example in BCD code, disposed on concentric tracks and readable in the radial direction, which numbers correspond to the current actual value of the control variable and are indicated in the second device (42) of the control desk (202).

16. Copying device constructed, arranged and adapted to operate substantially as herein described with reference to the accompanying drawings.