JPH0789198B2 - Exposure control method and apparatus for colored copying - Google Patents

Description

The invention relates to a method and a device according to the preamble of claims 1 and 2 of the claims.

[Conventional technology]

A method and a device of this kind are disclosed in German Laid-Open Publication No. 3437222.
It is known from the issue. This publication suggests a copying machine in which the film to be treated has a scannable mark (in particular an edge marking) in a three-dimensional arrangement for each original to be copied, said mark being used in a prior scanning process. Is performed by an automatic device known in the art. However, in this case, there is a stamping device of this kind for edge marking at a corresponding position in the vicinity of the copying station in the copying machine, and each image position after the automatic transfer for a predetermined stroke length is not effective when the punch is operated. Films without edge markings of the above type can also be processed if monitored by an operator. However,
There is no difficulty in incorporating the punch in the vicinity of the copying window, and the scanning method by visual image position adjustment when scanning the entire film is very time consuming.

In the device known on the return path of the film during the copying process, when tracking the edge markings, the relevant image eigenvalues measured and stored during the first process and the same original eigenvalue for the entire film are often used for each original. The copy data is calculated and becomes the basis of the copy process. This requires accurate storage of each ordinal number of the original to be copied when copying only a single original by automatic setting, and also requires a complete analysis of all the copied originals present on the film.

[Problems to be Solved by the Invention]

The subject of the present invention is a film not provided with an edge marking,
It is possible to process all copyable originals that are not intended to be copied, without the additional drawbacks of a complete analysis on the film and post-edge marking.

[Means for Solving the Problems]

According to the present invention, based on not only the color density values (original characteristic values) of originals to be copied, which are obtained by regional photoelectric scanning, but also based on the color density values (original characteristic values) of many originals of the same film. An exposure control method for colored copying in which the amount of copying light is calculated for three colors and the scanning in the copying station is performed over time in the copying process performed from the first process to the second process. Only the film eigenvalue over
In addition, it is possible to solve the problem by measuring the original value of the original after the centering of the original to be copied and before the copying exposure in the copying station. It is also possible to measure the color density values of all the films during the first step to determine the film fixed values, without the provision of an exact measuring area for the original copy. Furthermore, by analyzing the measured values from the individual original areas, it is possible to exclude from the analysis areas with high transparency to which an imaging system is to be attached, for example according to the teaching of DE-OS 2840287. The film eigenvalues for calculating the three types of copying light rays for each individual original are the same for all originals of this film, and it is not necessary to record which original this value corresponds to.
Preferably, during the second step of the film to be copied in the reverse direction, such as the first step, for example, the eigenvalues of the original are measured after the copy original has been centered on the copy window by the employee and before the copying process is started. Then, this is related to the calculation of the three types of colored copying light rays together with the film eigenvalues corresponding to all the films. The calculation of these three types of colored copying light rays needs to be performed only for the original to be actually copied. The centering of the original with respect to the copy window before copying by the operator does not require any marking equipment attached to the image position, and in some cases, additional installation is possible.

The apparatus for carrying out the method according to the invention is provided with a partially transmissive mirror or oscillating mirror in the scanning position which always remains in the active position during the measurement of the film eigenvalue, which is used to measure the original eigenvalue in the copy window of the respective copying station. It is characterized in that it can be moved to the working position between the positioning of the original and the start of the copying process.

〔Example〕

Hereinafter, other features and advantages of the present invention will be described in detail with reference to the accompanying drawings.

The illustrated copying machine corresponds in essential outline to the machine described in DE-A 3437222. Therefore, only the cross-sectional view by the gaze method of the film transfer device, which can best understand the difference from the device according to German Laid-Open Patent Publication No. 3437222, is shown.

In the drawings, reference numeral 1 denotes an optical axis of an image forming light path in a conventional copying apparatus, and a lamp chamber (not shown) having a color copying function is provided in a rigid hole 11 so that the light is evenly distributed on the original table. Supply to 2. This will be described in more detail below. The original 10 located on the original stand is a zoom lens 24
To form an image on a photosensitive copy support (not shown), especially colored copy paper.

The original table 2 comprises two rails 8 and 9 supporting the film edges, the grooves of which allow the boundaries to guide the side edges of the film. The film strip 10 is free to move in the longitudinal direction on the rails 8 and 9 together with the original. However, the rail 9 on the side opposite to the operator is provided with a notch, and the pair of transfer rollers 20 and 21 are engaged with the notch. The lower roller 21 can freely rotate about a fixed axis, while the upper roller 20 is connected to a gear belt pulley 17 via a shaft 19, and this pulley is connected via a gear belt 15 to a gear belt pulley of the electric motor 12. Connected with 12b.
The motor 12 is mounted on a support 13, which can be pivotally arranged on the pedestal for removing the transfer roller 20 from the film.

Above the opening for the original to be copied, which is located between the rails 8 and 9, the pressing plate 3 is arranged on the rear rail 9 so as to be pivotable about an axis parallel to the longitudinal direction of the film. For example, a pressing plate 3 which can also be formed as an opening with a U-shaped engagement support for the side edge of the negative to be copied.
Supports an arm 9a on the other side of the bearing axis and connects it to a bell crank 6 via a continuous rod 4.
Similarly, the bell crank 6 is also fixed to the pedestal and is supported so as to be rotatable about an axis parallel to the film transfer direction, and the mirror 7 is supported on the leg portion 6a on the apparatus side. The other leg is provided with a fork-shaped slit guide for engaging the pin 5b with the lift arm 5a of the rotary magnet 5. This arm 5a of the rotating magnet can rotate about 120 ° clockwise,
Mirror 7 based on the transfer characteristics of pin / slit couplings 6b, 5a, 5b
Is pivoted away from the area of the imaging beam path of the copier. The arm 6c brings the mirror 7 into a plane pressing state via the connecting rod 4 accompanied by the turning of the mirror 7 and the arm 3a which is angled with respect to the pressing plate 3.

In its working position (that is, the turning position), the mirror causes light coming from the mirror hole 11 to enter the zoom lens 22 through the original 10 together with information, and the zoom lens forms a reduced image of the original on the photoelectric device 22. Project on the image window of. The optoelectronic device is composed of three measuring cell scan lines which are juxtaposed to one another as far as possible and which accept an original strip running transversely to the film transport direction, taking into account the mirror deflection.
The measuring cell scan line 23 becomes sensitive through the corresponding colored filter in each of the three basic colors and in width is approximately 1/15 of the length of the original image. The light receiver 23 is arranged on a skid 16 which is movable in the film running direction, and the skid is movable by a motor 18 over the length of the original image formation. The objective lens 22 is a zoom lens, and it is possible to form images of various different original knits on the photodetector 23 in terms of knitting.

The mode of operation of the above device will be described below.

The device is particularly suitable for processing individual film strips which do not have edge markings associated with individual image areas. An operator, who is in front of the device on the right side of the image, introduces the beginning of the film strip between the transfer rollers 20 and 21 in a position perpendicular to the supporting plane on the rails 8, 9. Then, the motor 12 of the transfer unit is energized. The measuring cell scan line 23 remains unchanged in its initial position during the first scanning process, where the strip is impinged by a beam of light along the whole corresponding to one of the side edges of the original window. In the lamp chamber, white light is made incident on the original copy through the rigid hole 11, and the entire area of the entire original copy of the film is sequentially imaged onto the measuring cell scanning line 23 through the objective lens, while the film is rolled. 20, 21 and the motor continuously feed from the left side of the device to the right side into the receiving device located there. The response cycle of the measuring cell scan line is controlled in synchronism with the transport speed of the motor 12 and is scanned in perfect sequence with respect to the measuring position on the film. Extremely transparent areas, such as in film openings or image stems, can be excluded from consideration by corresponding programming of the analysis computer. After passing, all measurements for all three colors of the film are stored in memory. This memory calculates so-called film eigenvalues, for example according to the teaching of DE-OS 2840287.

In the subsequent copying period, the entire or individual originals of the film strips are moved to the copying position via motorized film transfer 20, 21 with operator monitoring and control, or the film is transferred by conventional means. Press plate 3 from the front
It is also possible to move down to the position where the original to be copied is located in the original window. To start the copying process, the mirror 7 is still in its working position (shown). The mirror thus projects via the objective lens 22 a reduced image of the original to be copied in the area of the measuring cell scan line 23. In the starting position of the measuring cell scan line 23, these are located, for example, on the left edge of the original image. The motor 18 then moves the measurement cell scan line 23 above the original image, thus providing the computer with the measured values of all three colors in the entire area of the original to be copied (ie, the basis for calculating the original eigenvalues). position).
From both groups of values, the calculation of the copying light dose is then carried out in three colors, which is limited, for example, by the swiveling of the subtractive filter in the white copying light path of the lamp chamber. Before starting the copying process, the magnet 5 is energized and the mirror 7 is removed from the copying beam path by the clockwise pivoting movement of the arm 5a. At the same time, the original is brought into a precise plane position by the pressing plate 3 to give a clear image on the copy material. During the measurement, the plane position thus defined is not required in the imaging plane.
Because the measurement range is about 1/10 to 1/15 of the original size,
And, within this range, it can be integrated without difficulty due to defocus.

After the exposure or the three-color exposure is completed, the mirror 7 returns to the position shown in the figure to release the film pressing. The movement of the film until the positioning of the next original to be copied can be carried out, for example, by an operator, and the entire original to be copied of this film can be subjected to the copying process without the need for position marking. .

The operator's observation of the original is effected either through a corresponding opening in the rigid bore 11 or by a branch of the partial ray path behind the objective lens 22 for a suitable viewing device.

The periphery of the mirror 7 is formed in a light-tight manner so that it can also serve as a closure. However, further closures can also be provided behind the mirror.

The oscillating mirror 7 may be replaced by a fixedly arranged partially transmissive mirror if a sufficient light intensity is not required for measurement and copying.

The relative movement between the original image and the measuring cell scan line 23 can also be realized by a corresponding rocking system for the mirror 7.

However, the measurement cell scan line 23 on the skid 16
Alternatively, a mesh system of measuring cells 23 'can be provided, in which case an additional halo with three colored filters of the three primary colors is additionally arranged between the objective lens and the measuring cell mesh 23'.

In doing so, it is necessary to correlate the film transfer by the motor 12 with the film fragment size approximately the length of the original copy during the first step of the film. In this case, the motor 12 is rationally configured as a step motor, which performs a transfer step of a number corresponding to the image length, and then, through a computer, determines the entire image range of this film segment in all three colors. Command. For this reason, it is often necessary to replace the colored filter in the measuring beam path after the scanning process. These measured values are supplied to the memory. After the measurement is completed, the film is transferred again for the path length corresponding to the image length. In that case, this does not play a role in the presence or absence of image stems in the measurement area currently being scanned, or in the analysis of numerical values of this kind by corresponding thresholding as described above.

In order to measure the original eigenvalue, the motor 18
No need to move the measurement system by. Rather, centering the image window of the original to be copied images the original area currently being measured onto the photoelectric mesh system 23 '. Of course, the measurement is repeated three times, each interposing one of the other colored filters.

By placing a dichroic ray distributor in the measuring ray path and a measuring cell network 23 'behind it which is sensitive to the basic color, it is possible to avoid three back and forth scans.

With the above method, instead of a subtractive lamp chamber, an addendum with three light sources for each one color or with one light source and a replaceable additional filter can be used.

[Brief description of drawings]

FIG. 1 is a sectional view of the copying apparatus of the present invention outside a copying window equipped with an observation device in the film transfer direction. 3 ... Holding device, 7 ... Mirror 10 ... Original, 16 ... Skid 20, 21 ... Film transfer device 22 ... Objective lens, 23 ... Measuring cell scanning line

Claims (7)

[Claims] 1. Three colors based on color density values (original characteristic values) of respective originals to be copied obtained by regional photoelectric scanning, as well as color density values (original characteristic values) of a large number of originals of the same film. In an exposure control method for colored copying in which the amount of copying light is calculated and the scanning in the copying station is performed over time in the copying process performed from the first process to the second process, in the first process, the film eigenvalue of the film over the film length is determined. An exposure control method for colored copying, wherein only the measurement is performed, and the measurement of the original value of the original is performed at the copying station after the centering of the original to be copied and before the copying exposure. 2. An apparatus for carrying out the method according to claim 1, comprising a copying station provided with a device for performing an area-wise photoelectric scan of the original, and a storage device for the measured values of the original copies of a number of films. The scanning device is equipped with a partially transmissive mirror or oscillating mirror (7) that always stays in the operating position when measuring the eigenvalue of the film, and positions the original (10) in the copy window of the copying station to measure the eigenvalue of the original. A device which can be moved to the working position between the start of the copying process and the start of the copying process. 3. A scanning device connects the original (10) behind a mirror (7) on a system of three parallel measuring cell scan lines (23) sensitive for each color, which acts as a measuring device. The measuring cell scanning line (23) provided with an objective lens (22) for imaging
Is placed on a skid (16) that can move in the longitudinal direction of the film over a path corresponding to the length of the original image, and the skid (16) is stopped to measure the eigenvalue of the film and the film is continuously transferred by a film transfer machine. And the copy source is held stationary at the copy window to measure the image eigenvalues and the skates are moved over the image length or the image of the source is transferred to the measuring cell scan line (23) by rotation of the mirror (7). The device according to claim 2, wherein the device can be moved relative to each other. 4. The measuring device is one or more planar rows (23 ') of photosensitive cells, in front of which another measuring filter can be installed for each color measuring process. The device according to claim 2. 5. The copying window is provided with at least one holding device (3) effective for maintaining the copying process and an observing device for the original document. The device according to paragraph. 6. Device according to claim 5, characterized in that the holding device (3) for the original and the rocking mirror (7) are connected so that they act alternately. 7. A transfer device (20, 21) is arranged in parallel with a copying window in a motor type film which operates when measuring the film eigenvalue, and the transfer device is manually adjustable back and forth during the copying period, or the transfer is manually performed. 7. A device according to any one of claims 2 to 6, characterized in that it can be carried out at