JPH07101281B2 - Automatic exposure amount correction device and photometric device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an automatic exposure amount correction apparatus used in combination with a photographic printing apparatus that controls exposure by LATD (Large Area Average Transmission Density) The present invention relates to a suitable photometric device.

[Conventional technology]

In a conventional large-scale lab system, a photographic printing apparatus is used which measures LATD to obtain an exposure amount and prints based on the exposure amount. According to such a LATD method, in the case of a general negative in which there is no difference between the density of a main subject such as a person and the average density of the entire screen, it is possible to produce a print photograph with an appropriate density for both the person and the background. it can.

However, user negatives include those in various states, and it is difficult to print all negatives by the LATD method. That is, for example, a density fuer negative such as "a person on a light background" or "a person on a dark background", or one bright color (R, G, B, C, M,
In the case of color area negatives in which any one of Y, or a combination thereof, occupies a large area, printing at the average density of the entire screen makes the person darker (overexposed) or lighter. It becomes impossible to obtain a print photograph with proper density and color balance, because the main subject is affected by (exposure under) or the color occupying a large area.

Therefore, in order to deal with these subject areas, a negative test is performed in advance, and the LATD
The exposure amount according to the method is corrected. In addition, recently, in order to perform exposure control with high accuracy, the negative is measured at a large number of points, and the characteristics of the negative pattern are statistically determined based on the photometric value. There is also provided a photographic printing apparatus that calculates an exposure amount using the area characteristic value and LATD and prints it.

[Problems to be Solved by the Invention]

However, the existing LATD method photographic printer does not have an automatic exposure amount correction function to prevent the occurrence of subject areas, and it is corrected by a negative test in the notcher / puncher, which is the preprocessing stage of the printer. There is. Since this negative test is carried out manually, there is a problem that there is a limit to the efficiency improvement. Moreover, since skill is required, it is difficult for a beginner to efficiently and quickly produce a photograph having an appropriate density and color balance.

Further, it is also possible to simply separate the automatic exposure amount correction function of the photo printing apparatus for correcting the exposure amount according to a negative pattern or the like from the photo printing apparatus and attach it to the photo printing apparatus of an existing large-scale laboratory. . However, in this case, since the processing capacity of the photo printing apparatus in a large-scale laboratory and the calculation processing capacity of the automatic exposure amount correction device are different, the calculation processing speed per frame is slower than the printing processing speed, so that the automatic exposure amount is When the correction device is connected, there is a problem that the processing capability of the photo printing device is reduced.

The present invention has been made to solve the above problems, and even in a laboratory system that does not have an existing automatic exposure amount correction function, the automatic exposure amount correction function can be easily added.
Moreover, it is an object of the present invention to provide an automatic exposure amount correction device and a photometric device that do not reduce the printing capacity.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a frame feeding means for sequentially feeding the photographic film by a frame, a sensor for photometrically measuring each point of the frames sequentially fed to the photometric position by the frame feeding means, and a photometric value from the sensor. Is connected between the sensor and the plurality of calculating means for calculating the exposure correction data based on the above, and the photometric value from the sensor is sequentially sent to each of the plurality of calculating means for each frame. An automatic exposure amount correction device and a photometric device for printing are constituted by the photometric value output switching means.

[Action]

Each point of a frame recorded on a photographic film, for example, a negative film, is metered by a sensor. When the photometry is completed, the photographic film is fed by a frame, the respective points of the next frame are measured, and the respective points of the respective frames are sequentially measured in the same manner. The photometric value of each frame from the sensor is sequentially sent to any one of the plurality of arithmetic units by the photometric value output switching circuit. Therefore,
Since the exposure correction data are successively calculated in frame order based on the photometric value in the plurality of calculation units, as a result, the calculation processing can be performed at high speed according to the number of calculation units. This allows
The exposure amount can be automatically corrected without lowering the processing capability of the photographic printing apparatus in a large-scale laboratory capable of high-speed printing exposure.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 indicates an existing photo printing apparatus. light source
White light emitted from 10 is diffused by a diffusion box 11 and then illuminates a color original image, for example, a color negative film 13 set on a negative carrier 12. Color negative film 13
Is 3 in the automatic exposure amount correction device (scanner) 2 described later.
Transferred to this negative carrier 12 after color separation photometry,
After the exposure for printing is completed, the film is taken up by the take-up reel 14.

An image forming lens 15 is arranged above the negative carrier 12 and forms a negative image on the color paper 16 set at the exposure position. In addition, color paper 16 and imaging lens
Cyan, magenta, and yellow filters 18 to 20 that are selectively inserted by the filter driving unit 17 are arranged in the printing optical path between the filters 15 and 15. A shutter 21 is arranged above each of the filters 18 to 20.
Is inserted into the printing optical path by the shutter drive unit 22, and the exposure amount is adjusted.

Further, a photometric unit 25 including a lens 25A and a light receiving element 25B provided for each color is disposed obliquely above the negative carrier 12. The LATD of each color measured by this metering unit 25 is
After being converted into an electric signal and amplified by the photoelectric conversion amplifier 26, A /
The signal is converted into a digital signal by the D converter 27, logarithmically compressed by the logarithmic converter 28, and sent to the controller 29 as a photometric gain value D _i (i represents any one of red, green, and blue). The controller 29 is composed of a well-known microcomputer, and automatically calculates the exposure amounts of the three colors by an exposure amount calculation formula described later based on the photometric gain value D _i , the negative test result, and the like. 3 each based on this calculation result
Adjust the timing of inserting the color filters 18 to 20 into the printing optical path. That is, based on the exposure amounts of the three colors, the corresponding color filters 18 to 20 are inserted into the printing optical path when the exposure amounts are sequentially reached, and the colors that have reached the predetermined exposure amount are cut.

Further, a notch sensor 23 for identifying the frame of the negative film 13 is provided on the film exit side of the negative carrier 12. By counting the notch detection signal from the sensor 23, the frame set on the negative carrier 12 and the notch count number N of the correction data from the automatic exposure amount correction device 2 are made to correspond to each other, and the frame to be printed and exposed. The correction data of the pieces are combined correctly.

An automatic exposure amount correction device 2 is installed near the negative film entrance side of the existing photo printing device 1. The automatic exposure amount correction device 2 calculates the exposure amount correction data of the photographic printing device 1 by performing three-color separation photometry on the negative film 13 to be photographic printed beforehand. The white light emitted from the light source 30 is diffused by the diffusion box 31, and then illuminates the color negative film 13 set in the negative carrier 32. An imaging lens 35 is arranged above the negative carrier 32, and
A negative image is formed on the image pickup section of the color image area sensor 36 including D and the like.

Further, a notch sensor 37 for identifying the frame position of the frame at the photometric position is arranged near the negative carrier 32. This sensor 37 is a notch sensor of the photoprinting apparatus 1.
It is constructed similarly to 23. The piece identification data from the notch sensor 37, that is, the notch count number N is sent to the controller 38. The controller 38 controls each part based on the notch count number N, and is composed of a microcomputer.

The photometric value from the color image area sensor 36 is the first
Is sent to the switching circuit 39. The first switching circuit 39 is 3
One of the arithmetic units 40A to 40C provided in this order is selected in order, and the photometric value from the image area sensor 36 is output to this. Each of the calculation units 40A to 40C is composed of a microcomputer, and automatically calculates the correction data of the three colors represented by the number of steps of the correction key based on the three-color separation photometric value of each point. To the second switching circuit 41. The second switching circuit 41 is provided for each arithmetic unit 40.
The correction data sequentially output from A to 40C is output to the addition circuit 42. The adder circuit 42 adds the correction data from the paper tape reader 50, which will be described later, and the correction data from the arithmetic units 40A to 40C. The added correction data is stored in the controller 38
It is written in the storage unit 43 at the address designated by the notch count number N by the control signal from. The written correction data is output together with the notch count number N to the controller 29 of the photoprinting apparatus 1 as correction data in the same format as a conventional paper tape reader.

In order to set the negative film 13 on the negative carrier 32, a conveying roller pair 44 is arranged on the film exit side of the negative carrier 32. The conveyance roller pair 44 is driven by a pulse motor 45, and the pulse motor 45 is controlled by a controller 38 via a driver 45A. Also, the negative carrier 32
On the film entrance side, a reel 46 in which the negative film 13 is wound and accommodated, and a guide roller 47 for guiding the negative film 13 from the reel 46 to the photometric position of the negative carrier 32 are arranged.

A guide roller for guiding the negative film 13 from the automatic exposure amount correcting device 2 at the same height as the conveying roller pair 44 and at the negative film entrance side of the photoprinting device 1.
48 have been added. Further, in order to form a free loop between the guide roller 48 and the conveyance roller pair 44 of the automatic exposure amount correction device 2, a predetermined gap is provided between them. In addition, on the side plate of the automatic exposure amount correction device 2,
A guide plate 49 for guiding the bottom of the free loop when the free loop is formed is rotatably attached via an attachment shaft 49A.

In addition, the automatic exposure amount correction device 2 includes a paper tape reader 50.
Is provided. The paper tape reader 50 reads correction data pre-verified by an operator in accordance with the punching pattern of the paper tape 51 and outputs it to the adding circuit 42. The reel 52, the guide roller 53, and the tape reader 54 are used to read the correction data. It is configured.

The automatic exposure amount correction device 2 reads the correction data pre-verified by operating the paper tape reader 50, adds the correction data and the correction data obtained by photometry, and adds the correction data to the photoprinting device 1 Mode selection key 60 so that you can select the pre-verification mode to send to the controller 29 of the, and the unattended mode in which the negative film 13 is directly set without performing this pre-verification and only the automatic exposure amount correction by photometry is performed. , 61 are provided on the keyboard 62.

Next, the operation of this embodiment will be described.

First, the pre-verification mode when the pre-verification mode selection key 60 is operated will be described. The color negative film 13 is previously tested by a negative tester, and the correction data (MK ₁ , MK ₂ ) based on the test result is recorded on the paper tape 51. Where MK
₁ represents the number of steps of the density key, and MK ₂ represents the number of steps of the color key. This correction data (MK ₁ , M
K ₂ ) is rough data such as + correction, −correction, and no correction. The paper tape 51 is set in the paper tape reader 50, and the read correction data (MK ₁ , MK ₂ ) is added by the addition circuit 42.
Sent to.

In addition, the certified negative film 13 is set in the automatic exposure amount correction device 2, where the correction data (SK ₁ , SK ₂ ) by the three-color separation photometry is sequentially automatically calculated by the exposure amount calculation units 40A to 40C for each frame. Is calculated. That is, first, for example, the photometric value of the first frame is output to the first arithmetic unit 40A by the switching circuit 39. When the photometry of the first frame is completed, the negative film 13 is transferred by one frame, and then the photometry of the second frame is performed. This photometric value is output to the second arithmetic unit 40B by the switching circuit 39. Similarly, when the photometry of the second frame is completed, the photometry of the next third frame is performed, and this photometric value is set to the third value by the switching circuit 39.
Is output to the operation unit 40C of. When the photometry for the third frame is completed, the photometry for the next fourth frame is performed, and the photometric value is output to the first arithmetic unit 40A. Thereafter, photometry is similarly performed one after another, and the photometric values are sequentially output to the exposure amount calculation units 40A to 40C.

Each arithmetic unit 40A~40C calculates the correction data of each frame (SK _1, SK ₂₎ by the following procedure. First, when the divided photometric value is input from the image area sensor 36, pre-processing is performed to facilitate extraction of the feature of the divided photometric value. Next, feature extraction is performed based on the photometric value processed in the previous stage, and pattern identification calculation is performed based on the extraction result. The pattern identification calculation is performed by performing identification processing using the identification parameter obtained from the extraction result and various correction programs. The correction data (SK ₁ , SK ₂ ) is calculated using the identification result of this pattern, the characteristic value of a specific point or area, and LATD.
Where SK ₁ represents the number of steps in the density key and SK ₂
Indicates the number of steps of the color key.

Further, the adding circuit 42 corrects the correction data (SK ₁ , SK ₂ ) and the correction data (MK ₁ , MK ₂ ) read from the paper tape reader 50.
Using and, the correction data (K ₁ , K ₂ ) is calculated from the following equation.

K ₁ = MK ₁ + SK ₁ K ₂ = MK ₂ + SK _{2 When} adding two correction data as in this embodiment, the correction data read from the paper tape reader 50 is used.
MK ₁ , MK ₂ ) is the correction data (SK ₁ , SK ₂ ) based on the photometric value
Then, auxiliary correction data for an image that is difficult to correct for correction is input.

The obtained correction data (K ₁ , K ₂ ) is sent to the storage unit 43,
It is written to the address designated by the number N of counts. The correction data (K ₁ , K ₂ ) written in is written in the controller 29 of the photoprinting apparatus 1 by the control signal of the controller 38.
Is output to. Since the format of this correction data is the same as the correction data from the paper tape reader 50, the photo printing apparatus 1 including the controller 29 is provided with the automatic exposure amount correction apparatus 2 according to the present invention without any modification. can do.

The number of the arithmetic units 40A to 40C to be installed is determined in consideration of the printing capability of the photographic printing apparatus 1 to which the automatic exposure amount correction apparatus 2 is attached. That is, the printing processing capacity of the photo printing apparatus 1 in the large-scale lab system is represented by the processing time T1 per frame, and the processing time T2 per frame in each of the arithmetic units 40A to 40C is T2. Since T2 takes several times as long as the printing processing time T1, in order to perform processing without lowering the processing capacity of the photo printing apparatus 1,
It is necessary to satisfy the condition of T1 ≦ m × T2 by using a plurality of arithmetic units. Therefore, m calculation units that satisfy m ≧ (T1 / T2) are installed. Therefore, in this embodiment, three arithmetic units 40A to 40C satisfying the above conditional expressions are installed.

The photographic printing apparatus 1 sequentially prints the negative film 13 which has been sent from the automatic exposure amount correction apparatus 2 and which has been subjected to the three-color separation photometry. First, the negative light 13 emitted from the light source 10 and sufficiently diffused in the diffusion box 11 illuminates the negative film 13 of the negative carrier 12. The negative image of the negative film 13 is measured by the photometric unit 25 on the LATD, and the photometric gain value D _i is calculated based on the LATD. Based on this photometric gain value D _i and the exposure correction data (K ₁ , K ₂ ) from the automatic exposure amount correction device 2, the optimum exposure amount E _{i is} calculated by the following equation.
Is calculated.

log E _i = LM _i × CS _i × (DN _i −D _i ) ＋ PB _i ＋ LB _i ＋ MB _i ＋ NB _i ＋ α × K ₁ ＋ β × K ₂ LM: Magnification slope coefficient, enlargement determined by negative type and print size It is preset according to the magnification.

CS: Color slope coefficient prepared for each type of negative, and there are two types, one for over and one for under, which is selected by judging whether the average density of the frames to be printed is under or over.

DN: Standard normal concentration value.

D: Photometric gain value based on the LATD of the print frame.

PB: A corrected paper balance value for standard color paper, which is determined according to the type of color paper.

LB: A corrected lens balance value for the standard print lens, which is determined according to the type of print lens.

MB: Master balance value that is commonly added to all negative types.

NB: Negative balance (color balance) value, which is determined for each type of negative.

α: Step width of the density key.

β: Color key step size.

The filter driving unit 17 is driven based on the optimum exposure amount E _i for each color calculated in this way. Filter drive unit 17
Are all color filters 18-20 when the shutter 21 is opened.
Is retracted from the printing optical path, and first, printing exposure with white light is performed. Next, the color filters 18 to 20 corresponding to the colors having reached the exposure amount E _i are sequentially inserted into the printing optical path to cut the color components.

In this way, the frame recorded on the color negative film 13 is printed on the color paper 16. When the photographic printing of one frame is completed, the color paper 16 is transported by one frame and the unexposed portion is set at the exposure position. Photographic printing can be performed on each frame based on an appropriate exposure amount E _i in the same procedure.

In addition, when selecting the unattended mode that does not perform the pre-verification, without considering the correction data from the paper tape 51,
The correction data (SK ₁ , SK ₂ ) is calculated by each of the arithmetic units 40A to 40C, and the optimum exposure amount E _i is calculated by the correction data (SK ₁ , SK ₂ ) to perform printing exposure.

Further, in the above-described embodiment, the exposure correction data is output by the number of steps (K ₁ , K ₂ ) of the density key and the color key, but instead of this, the exposure correction amount (α × K ₁ + β ×
It may be output as K ₂ ).

In addition, in the above-described embodiment, the addition circuit 42 adds the correction data by the verification and the correction data by the photometric value and outputs the result to the photographic printing apparatus 1. However, instead of this, the correction data by the verification is used. The correction data may be sent to the calculation units 40A to 40C, and the correction data may be calculated by using this correction data as auxiliary data for the calculation. Further, the exposure correction data can be output in the form of a coefficient by which (DN _i −D _i ) in the above exposure amount calculation formula is multiplied, instead of being expressed by the number of steps of the key value.

Further, in the above embodiment, the exposure method in which the color filters 18 to 20 are sequentially inserted from the color having reached the predetermined exposure amount E _i and the color components thereof are cut is adopted. The exposure amount correcting apparatus of the present invention can also be used for a photographic printing apparatus in which the quality is adjusted to control the exposure amount. In this case, since the logarithmic value of the exposure amount is the density, the controller refers to the color filter calibration curve showing the relationship between each filter set position and the density value, and for blue, yellow and for green. For magenta, and for red, the set position of the cyan color filter is obtained. And the current position of each color filter (photometric position)
And the difference in the number of drive pulses from the set position of each color filter is calculated. The calculated number of driving pulses is sent to the light quality adjusting unit, and based on this, each pulse motor is driven to operate the color filters to adjust the three-color light components of the printing light,
Proper exposure may be performed.

Further, in the above embodiment, the automatic exposure amount correction device is directly connected to the photographic printing device to correct the exposure amount, but the present invention is not limited to this, and the exposure correction amount is calculated. After that, it may be recorded on a recording medium such as a paper tape or a floppy disk and set in a paper tape reader or the like of a photo printing apparatus to correct the exposure amount.

Also, one sensor 36, a plurality of arithmetic units 40, and a switching circuit 3 for switching and outputting the photometric values from the sensor 36 to these
9. Further, the photometric device composed of the switching circuit 41 and the addition circuit 42 can be incorporated in a photographic printing apparatus or used in a negative proofing machine, in addition to this embodiment.

〔The invention's effect〕

As described above, according to the present invention, since the exposure correction data obtained from the photometric value of each point of the frame is output to the photographic printing apparatus having the automatic exposure amount control mechanism of the LATD method, it is highly accurate. Exposure control can be performed. That is, it becomes possible to easily and promptly produce a print photograph with an even more appropriate exposure amount for a density fuerage negative or a color fuer negative which cannot be appropriately printed and exposed only by the conventional LATD method. . Moreover, it is only necessary to add a guide roller on the film entrance side and install an automatic exposure amount correction device without major modification of the existing photo printing device, and it is possible to easily improve the performance of the existing photo printing device. become able to.

In addition, even in the case of a high-speed photoprinting device such as a photoprinting device in a large-scale lab system, the processing capacity of the photoprinting device is reduced because a plurality of arithmetic units are used in accordance with this processing capacity. Instead, the exposure amount can be corrected.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a state in which a photographic printing device and an automatic exposure amount correction device are connected. 1 …… Photo printing device 2 …… Automatic exposure amount correction device 25 …… Photometry unit 29,38 …… Controller 36 …… Color image area sensor 39,41 …… Switching circuit 40A-40C …… Calculation unit 50 …… Paper tape leader.

Claims (2)

[Claims] 1. An automatic exposure amount correction device which is connected to a photographic printing device and corrects the exposure amount of the photographic film, and a frame feeding means for sequentially feeding the photographic film by a frame, and the frame feeding means sequentially feeding the film to a photometric position. A sensor for photometrically measuring each point of the frame, a plurality of arithmetic means for calculating exposure correction data based on the photometric value from the sensor, and a photometric value from the sensor, which is connected between the sensor and a plurality of arithmetic means. An automatic exposure amount correction device, characterized in that it comprises a photometric value output switching means for sequentially sending each frame to one of a plurality of arithmetic means. 2. A frame feeding means for sequentially feeding the photographic film by a frame, a sensor for photometrically measuring each point of the frame sequentially fed to the photometric position by the frame feeding means, and exposure correction data based on the photometric value from the sensor. A plurality of calculation means for calculating, and a photometry value output switching means which is connected between the sensor and the plurality of calculation means and sequentially sends the photometry value from the sensor to one of the plurality of calculation means for each frame. A photometric device for printing, comprising: