JP2554744B2 - Photo film screen detector - Google Patents

Description

The present invention relates to an improvement of a screen detection device for a photographic film.

[Conventional technology]

Conventionally, an automatic film carrier or the like is provided with a screen detection device for automatically positioning a screen on an exposure window, a negative viewing window, or the like. This screen detection device is provided with about 4 to 10 photosensors at a predetermined pitch in the width direction of the film, and performs screen detection processing based on the output signals of these photosensors to detect the screen position. ing.

[Problems to be Solved by the Invention]

However, the above-mentioned conventional screen detection sensors are
And a light receiving section including a photodiode. For this reason, the screen density of the film is read in points, so that there is a problem in that the screen position detection accuracy decreases. Further, since a monochromatic LED is used as the light projecting portion, there is a problem that the color response is poor and the detection accuracy of the screen position is lowered.

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and an object of the present invention is to provide a screen detection device for a photographic film that improves the detection accuracy of the screen position.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an optical sensor formed by arranging a plurality of light receiving portions in a line at a predetermined pitch in the width direction of the film, and the optical sensor is provided on the side opposite to the optical sensor arrangement side of the film. The linear light sources are provided along the rows of the light receiving portions, the light receiving portions are formed in a strip shape in the width direction of the film, and the screen detection processing is performed based on the output signal of each of the light receiving portions. As the linear light source, a fluorescent lamp, a cold cathode tube or the like is used.

[Action]

The film is transferred after the linear light source emits light. As a result, the film is illuminated, and the transmitted light reaches a plurality of light receiving portions arranged in a row at a predetermined pitch in the width direction of the film, and is photoelectrically converted by each light receiving portion. The signal from the light receiving surface is sent to the controller, where the screen position detection processing is performed. The light receiving section is formed in a strip shape elongated in the width direction of the film, and the screen is not scanned in a line shape by dots but is scanned in a strip shape having a certain width. Accuracy is improved.

〔Example〕

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

FIG. 1 is a perspective view showing a state in which the screen detection sensor 10 is disassembled and viewed from the lower side. Below the transfer path of the negative film 11, a light projecting section including a fluorescent lamp 12 is arranged. . The light from the fluorescent lamp 12 passes through the slit 15 of the slit plate 14 and illuminates the negative film 11 from below. Slit plate 14
Is attached to the opening 16A of the attachment plate 16 from above.

The light transmitted through the negative film 11 is measured by the light receiving sensor 17. The light receiving sensor 17 includes five light receiving portions 22A to 22E on the back surface of the IC substrate 21 at intervals of 2 mm in the width direction of the negative film 11.
The glass plates 23 are arranged in a row and are joined together. In addition, one light receiving portion 22F is arranged in parallel with respect to the central light receiving portion 22C with a space of 1 mm in the film feeding direction. Light receiver 22A-22
F is composed of a well-known amorphous silicon photo sensor. Since amorphous can form a uniform and large-area film on a glass plate or the like, the light receiving portions 22A to 22F can be arranged in a strip shape and at a predetermined pitch as in this embodiment.

FIG. 2 shows the positional relationship between the light receiving portions 22A to 22F and the screens 11A of the negative film 11. Each of the light receiving portions 22A to 22F is formed in an elongated rectangular shape in the width direction of the negative film 11. The dimensions of each of the light receiving parts 22A to 22F are about 2.4 mm and the width is about 0.2 mm when detecting each screen 11A of the 135-type negative film 11. These light receiving parts 22A to 22
The band-shaped scan lines La to Le on the negative film 11 by E are shown in FIGS. The widths of the light receiving portions 22A to 22F are not limited to the above numerical values, and it is preferable to select within the range of 0.1 to 0.5 mm, for example. Further, in this embodiment,
Although the number of the light receiving units 22A to 22E is 5, the number can be appropriately increased or decreased. The range of increase and decrease is preferably, but not limited to, the range of 4 to 10. Further, the signal from 22F is for detecting the arrival of the negative film 11, but the light receiving section 22F may be omitted.

Also, on the IC substrate 21, the preamplifier I shown in FIG.
The -V conversion circuit 24 is incorporated. This preamp
The IV conversion circuit 24 amplifies the weak current signal photoelectrically converted by each of the light receiving units 22A to 22F and then converts it into a voltage signal. substrate
21 is attached to the opening 26 of the attachment plate 25 from above, and the glass plate 23 is fitted into the opening 26 that is suitable for this.

As shown in FIG. 3, the preamplifier / IV conversion circuit 24
After the gain is adjusted by the gain adjusting amplifier 27, the voltage signal from the signal is sent to the first and second characteristic value extraction units 28 and 30, where the characteristic values VMin and (VM
ax-VMin) is extracted. That is, the first extracting unit 28 extracts the minimum value of the voltage signals Va to Ve from each of the light receiving units 22A to 22E and sends it to the A / D converter 32 as the characteristic value VMin. In addition, the second extraction unit 30 extracts the maximum value from the voltage signals Va to Ve from the light receiving units 22A to 22E, sets it as VMax, and calculates the difference between this VMax and VMin from the first extraction unit. The characteristic value (VMax-VMin) is sent to the A / D converter 34. The signals digitized by the A / D converters 32 and 34 are output to the controller 40.
Sent to the I / O port 41 of the.

The controller 40 is composed of a well-known microcomputer, and has a control program stored in the ROM 42 and a RAM 43.
The CPU 44 processes the characteristic values from the A / D converters 32 and 34 based on the various data stored in. In addition to the screen detection data processing, the controller 40 controls the film feed pulse motor 46 via the I / O port 45 based on the data processing result to display the screen 11A whose edge position has been detected on the film carrier. The exposure window (not shown). Therefore, I / O port 41 has a negative film 11
A sensor 47 is provided for detecting the tip of the. Further, the controller 40 also controls various other mechanisms of the printer processor to which the film carrier is attached.
Therefore, a keyboard 48 for controlling various mechanisms is provided. The keyboard 48 has alphanumeric keys 49 for setting various modes and inputting negative test results.
Frame advance key 50 for frame-by-frame advance, fine adjustment key 51 for fine adjustment of frame position, start key
52 etc. are provided.

FIG. 4 shows voltage signals Va to Ve obtained when the negative film 11 and each screen 11A of the negative film 11 are scanned by the light receiving portions 22A to 22E.
Column and the characteristic values VMin, VMa extracted from each of these signals.
x, (VMax-VMin) as an example. As can be seen from the figure, the characteristic value VMin becomes smaller in the screen 11A and becomes larger in the blank negative portion which is the blank space 11B between the screens 11A. Therefore, the controller 40 can determine the edge that is the boundary between the screen 11A and the margin 11B by detecting the sudden change in the characteristic value VMin. In addition, the characteristic value (V
Max-VMin) becomes large in the screen 11A and takes a value close to "0" in the margin 11B. Therefore, the controller 40
Detects the position where the characteristic value (VMax-VMin) changes to "0" by the controller 38, and in the same manner, the edge position of the screen 11A can be determined. And
The final edge position of the screen 11A is judged by ANDing the judgment signals of these two characteristic values VMin and (VMax-VMin), whereby each frame of the negative film 11 is exposed to the exposure window of the film carrier. It can also be positioned on the negative sight glass.

This positioning is performed as follows. First, the leading edge of the negative film 11 is detected by the film leading edge detection sensor 47, and the film feed amount is detected by counting the number of drive pulses of the pulse motor 46 from this detection. Then, by this and the screen detection signal, the edge position of each screen 11A of the negative film is stored as the feed amount data from the tip, the negative film 11 is transferred based on this feed amount data, and each screen 11A is exposed. Position it on a window.

In the above embodiment, the characteristic values VMin, (VMax-VMi
n) is taken and the screen position of the negative film is detected by this AND signal.
It is also possible to detect the screen position with higher accuracy by referring to this signal. That is, the two characteristic values VMin,
When the edge on the side where the screen 11A is switched to the margin 11B is detected by (VMax-VMin), the detection signal Vf from the light receiving unit 22F shows the maximum value because the margin 11B is detected. This is because the light receiving section 22F is arranged 1 mm apart from the light receiving section 22C, and the width of the margin 11B is about 2 mm, so that the light receiving section 22F is always positioned above the margin 11B when the above edge is detected. Because there is. Therefore, it is possible to detect whether the margin 11B or not depending on whether the signal Vf has the maximum value.
For example, depending on the scene of the screen, a blank part similar to the blank space 11B is formed in the full width of the film, and if the width of this blank part is smaller than the width of the blank space 11B, the screen It is possible to improve the detection accuracy by avoiding erroneous detection of the blank portion inside the blank space 11B.

〔The invention's effect〕

As described above, according to the present invention, an optical sensor having a plurality of light receiving portions at a predetermined pitch in the width direction of the film is provided, and the light receiving portions are formed in a slender band shape in the width direction of the film. As described above, it is possible to scan the screen of the film in a strip shape having a certain width without scanning the dots with dots. Therefore, since the area to be scanned is enlarged, the detection accuracy of the screen position can be improved. Since the photo sensor is formed by arranging a plurality of light receiving parts in a row at a predetermined pitch in the width direction of the film, since each light receiving part is integrated in a line, each light receiving element is different from the conventional one. Does not need to be aligned and mounted with high accuracy, and the mounting becomes simple, and the edge detection accuracy does not deteriorate due to misalignment of the light receiving elements.

Also, since the light receiving part is formed in a strip shape elongated in the width direction of the film, the screen is scanned in a strip shape having a certain width, unlike the one in which the screen is scanned in a line shape by dots, so that the screen area is increased by the larger area. It is possible to improve the detection accuracy and reduce the influence of adhesion of dust or the like or dirt. Further, since the linear light source is provided on the side of the film opposite to the side where the photosensors are arranged, along the row of the light receiving portions of the photosensors, the photographic film can be scanned more surely in a band shape than when a point light source is used. . Moreover, due to the synergistic effect with the above-mentioned optical sensor, the detection accuracy of the edge of the screen can be further improved with a simple structure. In addition, by using a fluorescent lamp or cold cathode tube as a linear light source,
The color response is improved and the screen detection accuracy is improved as compared with the case of using D.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a main part of a screen detection device for a photographic film embodying the present invention. FIG. 2 is an explanatory view showing the positional relationship between the negative film and the light receiving portion for scanning the screen of the negative film. FIG. 3 is a block diagram of the screen detection device. FIG. 4 is an explanatory diagram showing a negative film, signals from respective light receiving portions when the screen of the negative film is scanned, and characteristic values extracted from the signals. 10 …… Screen detection sensor 11 …… Negative film 11A …… Screen 11B …… Margin 12 …… Fluorescent lamp 17 …… Light receiving sensor 22A to 22F …… Light receiving unit 23 …… Glass plate 28,30 …… Characteristic value extraction unit 40 …… Controller 46 …… Film feed pulse motor.

Claims (2)

(57) [Claims] 1. A screen detecting device for a photographic film which detects a screen position by scanning in the longitudinal direction of the film, wherein an optical sensor having a plurality of light receiving portions formed at a predetermined pitch in the width direction of the film is provided, and the light of the film is detected. A linear light source is provided on the side opposite to the sensor arrangement side along the row of the light receiving portions of the optical sensor, and the light receiving portions are formed in a strip shape in the width direction of the film, and screen detection is performed based on the output signal of each of these light receiving portions. A screen detection device for a photographic film, characterized by performing processing. 2. A screen detecting device for a photographic film according to claim 1, wherein a fluorescent lamp or a cold cathode tube is used as the linear light source.