JPH0311329A - Picture detector for photographic film - Google Patents

Abstract

PURPOSE:To scan a film in a band form by providing an optical sensor having plural photodetectors at a prescribed pitch in the breadthwise direction of the film and forming photodetectors in a long and narrow band in the breadthwise direction of the film. CONSTITUTION:A light projecting part consisting of a cold cathode-ray tube 12 is arranged under a transporting path of a negative film 11, and the negative film 11 is irradiated from below with the light from this cold cathode-ray tube 12 through a slit 15 of a slit plate 14. The light transmitted through the negative film 11 is measured by a light receiving sensor 17. This sensor 17 has 5 photodetectors 22A to 22E arranged at intervals of 2mm on the rear face of an IC substrate 21 in the breadthwise direction of the negative film 11. Thus, the negative film is scanned in a band form having a certain width to improve the picture detection precision.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a photographic film screen detection device.

[Conventional technology]

2. Description of the Related Art Conventionally, automatic film carriers and the like have been provided with a screen detection device in order to automatically position the screen in an exposure window, a negative viewing window, and the like. This screen detection device has about 4 to 10 optical sensors arranged at a predetermined pitch in the width direction of the film, and performs screen detection processing based on the output signal of each of these optical sensors to detect the screen position. ing.

[Problems to be Solved by the Invention] However, each of the above-mentioned conventional screen detection sensors
It consisted of a light projecting section consisting of a light emitting section and a light receiving section consisting of a photodiode. For this reason, since the screen density of the film is read at points, there is a problem in that the detection accuracy of the screen position is reduced. Furthermore, since a monochromatic LED is used as the light projecting section, there is a problem that the color response is poor and the accuracy of detecting the screen position is reduced.

The present invention is intended to solve the above-mentioned problems, and it is an object of the present invention to provide a photographic film screen detection device that improves the accuracy of detecting the screen position.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an optical sensor in which a plurality of light receiving sections are formed at a predetermined pitch in the width direction of the film, and the light receiving sections are formed in an elongated strip shape in the width direction of the film. Screen detection processing is performed based on the output signal of each light receiving section. In another invention, a fluorescent lamp or a cold cathode tube is used as a light projection part for illuminating the film of the above invention, and this is arranged along a row of light receiving parts of an optical sensor.

[Effect]

While the film is being transported, a light projecting section consisting of a fluorescent lamp or a cold cathode tube emits light. As a result, the film is illuminated, and the transmitted light reaches a plurality of light receiving sections arranged at a predetermined pitch in the width direction of the film, and is charged and converted at each light receiving section. The signal from this light-receiving surface is sent to the controller, where the screen position detection processing is performed. The light-receiving section is shaped like a long and narrow strip in the width direction of the film, and the screen is scanned not in a line of dots, but in a strip with a certain width. Improves accuracy.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the screen detection sensor 10 disassembled and viewed from below, and a light projecting section consisting of a cold cathode tube 12 is arranged below the negative film 11 transport path. There is. The light from the cold cathode tube 12 passes through the slit 15 of the slit plate 14 and illuminates the negative film 11 from below. The slit plate 14 is attached to the opening 17 of the attachment plate 16 from above.

The light transmitted through the negative film 11 is measured by a light receiving sensor 17. The light receiving sensor 20 has a glass plate 23 bonded to the back surface of an IC substrate 21, on which five light receiving sections 22A to 22E are arranged in a row at intervals of 2 ma+ in the width direction of the negative film 11. In addition, one light receiving part 22F is placed at an interval of one fence in the film feeding direction with respect to the central light receiving part 22C.
are arranged side by side. The light receiving sections 22A to 22F are composed of well-known amorphous silicon photosensors.

Since an amorphous film can be formed into a uniform and large-area film on a glass plate or the like, the light receiving parts 22A to 22F can be arranged in a strip shape at a predetermined pitch as in this embodiment.

FIG. 2 shows each light receiving section 22A to 22F and the negative film 1.
The positional relationship with each screen 11A of 1 is shown.

Each of the light receiving sections 22A to 22F is formed in a rectangular shape elongated in the width direction of the negative film 11. Each light receiving section 22A-2
The dimensions of 2F are approximately 2.4 m in length and approximately 0.2 m in width when detecting each screen 11A of 1.35 type negative film 11. These light receiving parts 22A~
Strip-shaped scanning line L on negative film 11 by 22E
a-L e are shown in FIGS. 1 and 4. Note that the width of the light receiving portions 22A to 22F is not limited to the above numerical values, but is preferably selected within a range of 0.1 to 0.5 tm, for example. In addition, in this embodiment, the light receiving sections 22A to 22E
Although the number is set to 5, this number can be increased or decreased as appropriate. This increase/decrease range is preferably in the range of 4 to 10, but is not limited thereto.Also, the signal from 22F is for detecting the arrival of the negative film 11, but this light receiving section 22F is omitted. Good too.

Also, on the IC board 21, there is a preamplifier shown in FIG.
An IV conversion circuit 24 is incorporated.

This preamplifier/IV conversion circuit 24 includes each light receiving section 22.
The weak current signal photoelectrically converted at A to 22F is amplified and then converted into a voltage signal. The board 21 has a mounting plate 250 opening 2
6 from above, thereby fitting the glass plate 23 into the opening 26.

As shown in FIG. 3, the preamplifier/IV conversion circuit 24
After the gain is adjusted by the gain adjustment amplifier 87, the voltage signal from the
where the characteristic value VMin for screen detection is sent to
, and (VMax - VMin) are extracted. That is, the first extracting section 28 extracts the minimum value among the voltage signals Va to ■e from the respective light receiving sections 22A to 22E, and sends this to the A/D converter 32 as the characteristic value VMin. Also,
The second extraction section 30 extracts the maximum value among the voltage signals Va to Ve from each of the light receiving sections 22A to 22E, and converts this into VMaX
Assuming that the difference between this V Max and VMin from the first extraction section is the characteristic value (VMax - VMin), the A/D
to converter 34. The signals digitized by each A/D converter 32 and 34 are sent to the controller 40 at ■10 ports 4
Sent to 1.

The controller 40 is composed of a well-known microcomputer, and based on the control program stored in the ROM 42 and various data stored in the RAM 43, the CPU 44
The characteristic values from each A/D converter 32 and 34 are data-processed. In addition to the screen detection data processing, this controller 40 also performs I1 based on the data processing results.
The film feed pulse motor 46 is controlled via the 0 boat 45, and the screen 11A whose edge position has been detected is positioned at the exposure window (not shown) of the film carrier.

For this reason, the I10 boat 41 is provided with a sensor 47 for detecting the leading edge of the negative film 11. Furthermore, the controller 4o also controls various other mechanisms of the printer processor to which the film carrier is attached.

For this reason, a keyboard 48 is provided for controlling various mechanisms.

The keyboard 48 includes alphanumeric keys 49 for setting various modes and inputting negative test results, a frame advance key 50 for advancing frame by frame, and a fine adjustment key for finely adjusting frame positions. A key 51, a start key 52, etc. are provided.

FIG. 4 shows an example of the voltage signals Va-Ve obtained when the negative film 11 and each screen 11A thereof are scanned by the light receiving sections 22A to 22E, and the characteristic values VMin, VMax, ( VMax −VM
In) - Examples are shown. As can be seen from the figure, the characteristics (11iV??in become smaller within the screen 11A,
The blank area 11B between each screen 11A is large in the negative area. Therefore, the controller 40 uses this characteristic value V
By detecting a sudden change in Min, it is possible to determine the edge that is the boundary between the screen 11A and the margin 11B. In addition, the characteristic value (VMax - VMin) is
It becomes large within 1A, and takes a value close to "0" in margin 11B. Therefore, the controller 40 can similarly determine the edge position of the screen 11A by having the controller 38 detect the position where this characteristic value (VMaX - VMin) changes to "0". and,
These two characteristic values VMin, (VMax −V
By ANDing the determination signals of Min ), the final edge position to the screen 11 is determined, and thereby each frame of the negative film 11 can be positioned in the exposure window or negative viewing window of the film carrier. .

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 from the time of this detection, the film feed amount is detected by, for example, counting the number of driving pulses of the pulse motor 46. . Using this and the screen detection signal, the edge position of each screen 11A of the negative film is stored as feed amount data from the leading edge, and the negative film 11 is transported based on this feed amount data to expose each screen 11A. Position it on a window, etc.

In addition, in the above embodiment, the characteristic values VMin, (VMa
x - VMtn), and the screen position of the negative film is detected using this AND signal.
In addition, it is also possible to perform even more accurate screen position detection by referring to the signal from the light receiving section 22F.

That is, the above two characteristic values VMin, (VMa
x -VMin), when the edge on the side where the screen 11A changes to the margin 11B is detected, the light receiving section 22F
Since the detection signal Vf from 11B detects the blank space 11B, it shows the maximum value. This is because the light receiving part 22F is placed 1 m apart from the light receiving part 22C, and the width of the blank space 11B is about 2 m. Therefore, when the above edge is detected, the light receiving section 2
This is because 2F is always located above the margin IIB. Therefore, depending on whether this signal Vf has the maximum value or not, the margin 1
1B or not can be detected. For example, depending on the screen scene, a blank section similar to the margin 11B is formed within the screen to fill the entire width of the film, and if the width of this blank section is smaller than the width of the margin 11B, , it is no longer possible to erroneously detect blank areas in the screen as blank spaces 11B, and the detection accuracy can be improved.

〔Effect of the invention〕

As explained above, according to the present invention, an optical sensor having a plurality of light receiving sections at a predetermined pitch in the width direction of the film is provided, and the light receiving sections are formed in an elongated strip shape in the width direction of the film. In this way, the screen of the film can be scanned in the form of a strip having a certain width instead of being scanned point by point. Therefore, since the area to be scanned is expanded, the accuracy of detecting the screen position can be improved. Moreover, since the density of the screen is detected using a rectangular surface rather than a point, the influence of dust and dirt can be reduced. Furthermore, since a fluorescent lamp or a cold cathode tube is used as the light source of the light projecting section, false response is improved and screen detection accuracy is improved.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the main parts of a photographic film screen detection device embodying the present invention. FIG. 2 is an explanatory diagram showing the positional relationship between a negative film and a light receiving section that scans 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 each light receiving section when its screen is scanned, and characteristic values extracted from these signals. 10...Screen detection sensor 11...Negative film 11A...Screen 11B...Margin 12...Cold cathode tube 17! - Light receiving sensors 22A to 22F... Light receiving section 23, 28° 40, 46,... Glass plate 30... Characteristic value extraction section, - Controller... Film feed pulse motor. ζ− (,)

Claims (2)

[Claims] (1) In a photographic film screen detection device that detects the screen position by scanning the film in the longitudinal direction, an optical sensor is provided in which a plurality of light receiving sections are formed at a predetermined pitch in the width direction of the film, and the light receiving section is 1. A screen detection device for photographic film, which is formed into an elongated strip in the width direction of the film, and performs screen detection processing based on output signals from each of these light receiving sections. (2) In a photographic film screen detection device that detects the screen position by scanning the film in the longitudinal direction, an optical sensor is provided in which a plurality of light receiving sections are formed at a predetermined pitch in the width direction of the film. On the side opposite to the arrangement side, a fluorescent lamp or cold cathode tube is installed along the row of light receiving parts of the optical sensor.
A screen detection device for photographic film, characterized in that the light receiving section is formed in an elongated strip shape in the width direction of the film, and screen detection processing is performed based on output signals of each of the light receiving sections.