JPH0519367A - Negative film code deciding method - Google Patents

Abstract

PURPOSE:To improve the detecting rate of the code of a negative film without using a highly accurate optical sensor. CONSTITUTION:The code formed by development on the negative film F is detected by an optical sensor S, maximum and minimum extremal values are required from the output of the optical sensor S, obtained from the base part 41 of the code 40 and a code part 42, and a threshold corresponding to the base part 41 and the code part 42 is set based on the required specific extremal values and their front and rear values. Therefore, the base part 41 and the code part 42 are detected with the threshold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative film code judging method for judging a code formed on a negative film by development.

[0002]

2. Description of the Related Art In photographic printing, for example, a negative film is conveyed by a film conveying device, a frame of a negative image formed on the negative film is stopped at an exposure position, and the negative image is printed on a photographic paper by an exposing means. It is created by developing the photographic paper with a developing device.

When making this photographic print, an optical sensor detects the frame code or DX code formed on the negative film by development, and specifies the frame to be printed,
The printing conditions may be specified.

As an optical sensor for detecting a frame code, a DX code, etc. formed on the negative film, for example, an LED and a photodiode may be used for detection.
The output voltage from the photodiode at the base and the code of the negative film code is as shown in FIG. For such an output waveform, as the threshold L1 for discriminating the data of the base portion 51 of the code 50 of the negative film and the data of the code portion 52, a threshold voltage having a fixed value is set as shown in FIG. Alternatively, as shown in FIG. 7, there may be a case where two thresholds L2 are provided for moving from the cord portion 52 to the base portion 51 and two thresholds L3 for moving from the base portion 51 to the cord portion 52. ..

[0005]

By the way, the cord 50 of the negative film has, for example, a base portion 51 and a cord portion 5.
2 has a long cord (about 1.03 mm) and a short cord (about 0.46 mm). This code 50 is L
When detected by an optical sensor such as an ED and a photodiode, as shown in FIG. 8, the long code of the base portion 51 is followed by the short code of the cord portion 52, and then the base portion 51
When the short code portion of the code portion 52 is detected in the pattern P1 in which the long code of
Due to the influence of, the amount of light that hits the optical sensor is not sufficiently reduced.

On the contrary, the pattern P2 in which the short code of the base section 51 is located between the long codes of the code section 52
Then, the amount of light that passes through the short cord portion of the base portion 51 and strikes the optical sensor may be reduced. For this reason, the fixed threshold L1 may not be able to read the code of the portion where the output is insufficient, or the code may be mistaken for noise, and the negative film code 50
May be erroneously detected.

As described above, when the code 50 of the negative film is detected by using the optical sensor such as the LED and the photodiode, the output voltage thereof is the same code, for example, the code pattern before and after the code even if the code is a short code. May change due to.

Further, even if the code has the same pattern, the output voltage may change greatly depending on the type of the negative film, the developability, etc. Therefore, if the threshold for determining the base part and the code part is set to a fixed value, the code is erroneous. Often detected.

The present invention has been made in view of the above circumstances, and provides a code determination method for a negative film, which can improve the code detection rate of the negative film without using a highly accurate optical sensor. It is an object.

[0010]

In order to solve the above-mentioned problems, the negative film code judging method of the present invention detects a code formed by development on a negative film by an optical sensor, and the base portion of the code and the code. From the output of the optical sensor obtained from the section, find the extreme value that is the maximum and the minimum, and set the threshold corresponding to the base section and the code section based on this particular extreme value and the extreme values before and after this particular extreme value. Is characterized by detecting the base part and the code part.

[0011]

In the present invention, the optical sensor detects the base portion and the cord portion of the cord formed by development on the negative film,
From the output of this optical sensor, the extreme values that are the maximum and the minimum are obtained, and the threshold corresponding to the base portion of the cord and the cord portion is set based on this particular extreme value and the extreme values before and after it. The base portion and the cord portion of the cord are detected based on this threshold.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic view of a negative film conveying apparatus to which the present invention is applied, and FIG. 2 is a plan view of the negative film.

The negative film transporting apparatus 1 is provided in a printing apparatus which stops a negative image frame K formed on the negative film F at an exposure position and prints the negative image on photographic paper by an exposing means (not shown).

The negative film transporting device 1 is provided with a pair of transport rollers 2 and 3 for sandwiching and transporting both ends of the negative film F with a predetermined distance. A belt 6 is wound around the pulleys 4 and 5 of the conveying rollers 2 and 3 facing each other, and a sprocket 9 of a drive motor 8 is meshed with a sprocket 7 provided at an end of the conveying roller 2.

A stepping motor, for example, is used as the drive motor 8, and the transport roller 2 is rotated by the rotation of the drive motor 8.
Is rotated, and this rotational force is transmitted to the conveyance roller 5 by the belt 6, and both are rotated in conjunction with each other.
The film transport means A is configured to transport the film to the exposure position T.

A negative mask 10 is provided at an exposure position T between the conveying rollers 2 and 3, and the negative image of the frame of the negative film F is printed on a photographic paper (not shown) at this exposure position. A frame number confirmation viewer 11 of the negative film F is provided near the exposure position T so that the operator can visually confirm the frame number N1 of the negative film F, or the frame position on the negative film F can be confirmed. It can be conveyed so that the frame to be detected and printed at the exposure position T comes.

Screen detection sensors 12 and 13 are provided in the width direction of the negative film F near the transport roller 3.
Further, an optical sensor S for detecting the frame code N2 is provided at a position corresponding to the end portion of the negative film F, and this constitutes the information reading means B of the negative film F. When the negative film F is conveyed by the optical sensor S for printing by the film conveying means A, the negative film F is conveyed.
Of the frame code N2 is read, and the frame code N2 is detected by detecting the frame code N2.
You can see the piece number indicated by.

The frame code N2 and the frame number N1
Since the position of the frame code N2 is determined, the optical sensor S detects the frame code N2 at the same time.
The frame number N
The position of 1 can also be determined. Further, it is possible to detect how much the negative film F has been fed by counting the number of steps using a stepping motor as the drive motor 8 of the film feeding means A and measuring the output of the encoder attached to the feeding rollers 2 and 3. ..

At this time, the position of the frame number N1 attached to the negative film F is determined. For example, the optical sensor S reads the frame code of the negative film F being conveyed, obtains the frame number indicated by the frame code, and manages the position of the frame number N1.

Therefore, once the position of the frame number N1 can be confirmed, it is possible to know where the position of the frame number N1 has moved even when the negative film F is conveyed. Further, it is possible to calculate the distance information necessary to move the frame number N1 located on the opposite side to the exposure position T, for example, how many steps the stepping motor is moved.

Further, the DX code N3 may include a frame number. In this case, the optical sensor S constituting the information reading means B reads the DX code N3, and the DX code N3 is read.
It is also possible to detect the piece number from 3.

The read information from the optical sensor S and the detection information from the screen detection sensors 12 and 13 are sent to the control means C, respectively. A frame number input means D and a passkey input means E are connected to the control means C, and an exposure frame number of the negative film F to be exposed is input from the frame number input means D by an operator's operation. The control means C controls the film transport means A based on the input exposure frame number to transport a predetermined frame of the negative film F to the exposure position T.

When the negative film F is conveyed, the control means C can detect the feed amount of the negative film F. For example, if a stepping motor is used as the drive motor 8, for example, it can be calculated by counting the number of steps, or the conveying roller. When an encoder is attached to 2 or the transport roller 3, it is possible to detect from which position the negative film F is located by calculating from the number of steps, and it is accurately stopped at the exposure position T.

In the control means C, the position of the piece number N1 desired to be conveyed to the exposure position T and the position of the piece K in the vicinity thereof are collated from the information from the information reading means B, and the piece K closest to the inputted piece number. The negative film F is conveyed so that the image is at the exposure position T. When the negative film F is desired to be conveyed from the current position to a certain frame K, a frame number close to the frame K to be conveyed is registered in the control means C.

In the frame number input means D, an input is made manually or by a memory medium or communication, and the exposure axis position T
It is also possible to display not only the piece number of the piece at the position to be conveyed to, but also the position indicated by the piece number, for example, a half-size serial number display. In this case, for example, 1-
By registering 1A or the like in the control means C, the registered frame number is conveyed so as to come to the exposure position T.

Further, a passkey input means E is provided, and when the passkey input means E is pressed, the negative film F is conveyed.

The operator sets the exposure frame number to be conveyed to the exposure position T by setting the negative film F on the negative film conveying device 1 having the above-mentioned function and the frame number input means D.
Enter from. With this frame number input means D, the film conveying means A is controlled by the control means C by using, for example, manual input from a keyboard, input using a storage medium, communication means, etc., and the input exposure frame number is the exposure position. The drive motor 8 is driven to rotate the transport rollers 2 and 3 so that the negative film F can be transported so as to reach T.

At this time, the negative film transport device 1 can detect the frame position on the negative film F by the screen detection sensors 12 and 13, and the frame position on the negative film transport device 1 can be detected similarly to the frame number N1. It can be managed, and the frame can be stopped on the exposure position T.

As described above, after detecting the positions of the frame code N2 and the frame K and inputting the exposure frame number to be conveyed to the exposure position T as described above, the control means C causes the position information of the frame number and the position of the frame. The frame K that is the closest to the exposure frame number input by collating the information is the exposure position T.
The negative film F is conveyed so as to come to the bottom. When the screen near the frame number N1 cannot be detected, the negative film F is conveyed so that the frame number N1 is located on the exposure position T.

The optical sensor S for detecting the frame number of the negative film F is constructed as shown in FIG. 3, and the light shielding plates 30 having the slits 30a are arranged on both sides of the conveying path of the negative film F, and the slits 30a are provided. The LED 31 and the photodiode 32 are arranged so as to face the.

When the negative film F is conveyed, the LED 3
Optical sensor S composed of 1 and photodiode 32
When the frame code N2 is detected, the output voltage of the photodiode 32 has a waveform as shown in FIG.

That is, when a stepping motor is used as the drive motor 8, when the drive motor 8 moves one step, the negative film F is fed by a fixed amount (for example, 0.125 mm).
In the control means C, each time the drive motor 8 is driven by one step, the amount of light transmitted through the base portion 41 and the code portion 42 of the code 40 of the negative film F is converted into data by the output voltage of the photodiode 32 by an A / D converter or the like. And import. When the negative film F is conveyed and the cord 40 is sent to the sensor position as shown in FIG. 4, the cord portion 42 of the negative film F reduces the amount of light hitting the optical sensor S. You can see that you are coming.

The control means C stores the fetched data. When the code portion 42 reaches the sensor position, the amount of light that impinges on the optical sensor S gradually decreases, so that the value of the captured data also decreases. After that, when the code portion 42 is moved to the base portion 41, the amount of light that impinges on the sensor surface is increased, so that the value of the captured data is also increased. Thus, the code part 42 has a low extreme value, and the base part 41
Has a high extremum.

Next, the code 40 formed by development on the negative film F is detected by the optical sensor S, and the optical sensor S obtained from the base section 41 and the code section 42 of this code 40 is detected.
A detailed description will be given of a method of obtaining an extreme value having a maximum and a minimum from the output of.

First, the extreme value of the data taken into the control means C is detected. For this purpose, when the data D1 to D1 are fetched from the output as shown in FIG. 4, the data Dmin having the smallest value among the previously fetched data is compared. At the beginning of the code section 42, Dmin is Dmin = D
It will be 1 (the first captured data). Since the data D2 is D2 <D1, Dmin = D2. When the same operation is performed on the fetched data, Dmin = D5, and after moving the data D5, Dn <Dn + 1.
It can be seen that 5 is an extreme value.

At this time, since the data contains noise and the like, the waveform may be as shown in FIG. Where D
Data having n <Dm + 1 is set as an extreme value. Although the data D6 is originally a peak, the data D4 may have an extreme value. Therefore, after Dn <Dn + 1 holds, there is a certain difference or more (eg, 30% of the base voltage) from the extreme value data. The data is continuously compared until then, and when Dn is still the smallest, Dn is determined to be an extreme value. Since the cord 40 has the base portion 41 next to the cord portion 42,
Next, find the maximum extremum.

When the maximum extremal value data is obtained, the minimum extremal value of the read data is searched for with the maximum valued data as the initial value of Dmin. The peak can be obtained by the above method.

Next, a threshold corresponding to the base portion 41 and the cord portion 42 of the cord 40 is set based on the particular extreme value and the extreme values before and after the particular extreme value, and the base portion 41 and the cord portion are set by this threshold. The detection of 42 will be described.

First, consider H (n) of FIG. 4 as an example of obtaining the threshold L4 of the cord of the base portion 41. Since H (n) is the base portion 41, the maximum extreme value VHP
Have (n). Then, it has two minimal extreme values before and after it, which are defined as VLP (n) and VLP (n-1). The threshold VthH (n) of the code H (n) is obtained from the following three extreme values by the following equation. Here, γ is a constant (eg, γ = 1/2).

Of the sampling data between VLP (n-1) and VLP (n), the threshold VthH (n)
By counting the above data values, it is possible to determine whether H (n) is a long code or a short code.

Similarly, the threshold of the cord section 42 determines the extreme value of the code section 42 to be VLP (n) and the extreme values VHP (n) and VHP of the cords of the front and rear base sections 42.
From (n + 1) Can be asked.

By counting the data of VthL (n) or less among the sampling data from VHP (n) to VHP (n + 1), it is possible to determine whether the code is a long code or a short code.

For example, in the case of a frame code, the long code is about 1,30 mm, the short code is 0.46 mm, and if the feed amount of the negative film is 0,125 mm per step, it is above the threshold (or below). If)
If the number of data is 6 to 10, a long code, 5
If the number is two, it can be determined that the code is short.

In this way, it is difficult to detect the output of the long code and the short code portion sandwiched between the long codes by the conventional fixed threshold level method, but the output of the base section 41,
By setting the threshold according to the code section 42, it is possible to accurately determine whether the code is a long code or a short code.

[0046]

As described above, according to the present invention, the code formed by developing on the negative film is detected by the optical sensor,
From the output of the optical sensor obtained from the base part and the code part of this code, the maximum and minimum extreme values are obtained, and the threshold value corresponding to the base part and the code part is calculated based on this particular extreme value and the extreme values before and after it. Since the threshold and the base are detected by this threshold, the code error may occur even if the code pattern fluctuates or a negative film with a different base density is used without using a high-precision optical sensor. The code on the negative film can be correctly read without detection, and the code detection rate can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a negative film transport device.

FIG. 2 is a plan view of a negative film.

FIG. 3 is a configuration diagram of an optical sensor.

FIG. 4 is a diagram showing a code of a negative film and an output voltage of an optical sensor.

FIG. 5 is a diagram for obtaining an extreme value of the output of the optical sensor.

FIG. 6 is a diagram showing a code of a conventional negative film and an output voltage of an optical sensor.

FIG. 7 is a diagram showing a code of a conventional negative film and an output voltage of an optical sensor.

[Explanation of symbols]

 A film transport means S optical sensor C control means F negative film N1 frame number N2 frame code N3 DX code K frame T exposure position 30 slit plate 31 LED 32 photodiode 40 code 41 base part 42 code part

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[Procedure amendment]

[Submission date] July 16, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 8

[Correction method] Added

[Correction content]

FIG. 8 is a diagram showing a code of a conventional negative film and an output voltage of an optical sensor.

Claims (1)

Claim: What is claimed is: 1. A code formed by developing on a negative film is detected by an optical sensor, and the maximum and minimum values are obtained from the output of the optical sensor obtained from the base part and the code part of the code. The negative film characterized by setting the threshold according to the base portion and the cord portion based on this particular extreme value and the extreme values before and after the particular extreme value, and detecting the base portion and the cord portion by this threshold. Code determination method.