JPS5966778A - Retrieval device - Google Patents

Abstract

PURPOSE:To detect surely a mark and to prevent mis-retrieval regardless of the recording position of the mark, by lighting the mark of a picture part through a prism and interlocking the prism and a mark detector. CONSTITUTION:An optical member consisting of a wedge-shaped prism 25 is arranged between the condensor lens 15 and a glass plate 16. The prism 25 has a plane 251 in parallel with the film plane. A light (a) through the condensor lens 15 is made incident from the lower end face of the prism 25 and irradiated vertically from the upper end face 251. A mark detector 21 and the optical member 25 are fixed to a moving member 27. A screw rod 28 is fitted freely turnably to one end of the moving member 27. In turning an operating knob 30, the screw rod 28 is turned, the moving member 27 is moved and the mark detector 21 and the optical member 25 are moved interlockingly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for searching for a desired image on a recording medium by detecting marks on the recording medium.

Conventionally, the film used in search devices built into microfilm readers and the like has a counting mark on the side edge of each frame of the film, and by detecting this mark, the desired frame on the film can be found. It is set to search automatically.

The above search device illuminates the mark on the film with a lamp,
A mark detector detects changes in light blocked by marks when the film is moved 17, the output signal of this mark detector is counted by a counter, and the contents of the count of this counter and the desired frame number input from the keyboard are recorded. When the two match, the comparison circuit issues a stop signal to the drive control circuit, which stops the drive system that transports the film and brings the desired frame to a fixed position where it will be projected onto the screen. It is designed to let you do so. Normally, mark detectors have multiple photoelectric conversion elements to prevent false signals from being generated due to dust or scratches on the film, or to define the stop position of the frame, and mark the multiple photoelectric conversion elements. They are spaced apart from each other at slightly shorter intervals than the length of the film, and are arranged side by side in the direction of movement of the film.

The film illumination section of such a search device is constructed as shown in FIG. 1 is an illumination lamp, 2 ha-t lens, 5
, 4 are transparent glass plates placed oppositely with the film F in between, 5
is a projection lens, and 6 is a mark detector. The light beam emitted from the lamp 1 is condensed by a condensing lens 2 and illuminates the image area and mark of the film F. The image of the lamp 1 is formed at the pupil position of the projection lens 5. Generally, in a condenser lens, a large amount of light passes through the center of the lens, and the amount of transmitted light tends to decrease toward the periphery.

The mark detector 6 detects marks by interrupting the light beam passing through the condensing lens 2 with transparent or opaque marks. By the way, normally when an image is illuminated with the center of the illumination optical path and the center of the image coincident, marks are still recorded on the sides of the film, and light enters the mark portion obliquely. This combined with the properties of the condensing lens reduces the amount of light that enters the mark detector, making it impossible to reliably detect the mark, resulting in the search for the wrong image. . Particularly when using film in which marks are recorded far from the center of the image, the amount of light incident on the mark detector is extremely small.
It was difficult to search for information using this full frame.

In addition, if the image projected on the screen deviates from the predetermined position, the image is positioned by moving the film perpendicular to the feeding direction, but as the film shifts, the mark detector is activated. This requires movement, but this changes the amount of light incident on the mark detector, resulting in the problem of searching for the wrong image.

In order to solve this problem, it is possible to amplify the output signal of the mark detector using an amplifier with a high amplification ratio.
It has the disadvantage of being sensitive to noise and causing malfunctions. There is also a method of illuminating the image area and the mark with separate light sources, but this method has the disadvantage of being complicated and expensive.

The present invention has been made in view of the above circumstances.

To provide a search device that can efficiently illuminate a mark and perform a correct search regardless of the recording position of the mark or the position of a mark detector.

The details of the present invention will be described below with reference to the drawings.

FIG. 2 shows a microfilm reader to which the present invention is applied. In the figure, 11 is a supply reel;
2. 13 is a film guide roller, 14 is a lamp that illuminates the microfilm, 15 is a condensing lens that collects the light from rung 14, 16 and 17 are glass plates placed opposite each other across the film movement path, and 18 is a cap. A stun roller, 19 a pinch roller, and 20 a take-up reel. The supply IJ reel 11 and take-up reel 20 are connected to a film tensioning and winding motor, and the capstan roller 18 is connected to a film drive motor.

Microfilm F has a supply reel 11 and a take-up reel 20
The film is stretched between them, and is wound onto a take-up reel or rewound onto a supply reel by driving the capstan roller 18.

21 is a mark detector, and 22 is a projection lens that forms an image of the microfil μ on a screen 25.

FIG. 5 shows details of the illumination section, in which an optical member consisting of a wedge-shaped prism 25 is arranged between the condenser lens 15 and the glass plate 16. Prism 25 mark detector 21
placed below.

It has a plane 251 parallel to the film surface. The mark on the film passes between the mark detector 21 and the prism 25. Figure 4 shows the transmission state of light incident on the prism.
The light enters from the bottom surface of the prism, is refracted within the prism, and its direction changes. It shoots out almost vertically. The mark is illuminated by this emitted light, and the light transmitted through the film enters the light receiving surface of the mark detector 21 perpendicularly. Therefore, the amount of light incident on the mark detector is increased compared to the conventional method, and marks can be detected reliably.

The mark detector 21 and the optical member 25 are fixedly held by a movable member 27, and when the movable member 27 moves, they move together. A threaded rod 28 is rotatably attached to one end of the movable member 27, and when the threaded rod 2B rotates, the movable member 27 moves linearly in the direction of the arrow.

The threaded rod 28 is fitted into a fixed block 29 having a screw hole, and can be rotated by an operating knob 50 provided at its tip.

When the operating knob 30 is rotated, the threaded rod 28 is rotated, and as the threaded rod is rotated, the movable member 27 is moved in the direction of the arrow, and the mark detector 21 and the optical member 25 are moved in conjunction with each other. Therefore, when the film is moved in a direction perpendicular to the film feeding direction in order to position the image projected on the screen at a predetermined position, the position of the mark on the film changes, but the mark can be moved by turning the operating knob +50. When the mark detector 21 is moved to a position where it can be detected, the position of the optical member 25 changes in accordance with the movement of the mark detector, and the optical member always directs the light that has passed through the condenser lens toward the mark at a predetermined angle. placed in the position to be irradiated.

5. The mechanism for interlocking the mark detector and the optical member is not limited to the embodiment, and various interlocking mechanisms can be applied.

As shown in FIG. 5, the microfilm F has a frame 35 in which an image is recorded and a mark 36 on the side edge of each frame that has a different density from the periphery. At this time, the frame is illuminated by light from a lamp 25, and an image of the illuminated frame is projected onto a screen 26.

As shown in FIG. 5, the mark detector 21 includes a movable substrate 41 having an opening 40 and a guide member 42 made of an optical fiber bundle.
．． 45, and one end of each party guide member passes through the through hole of the first block 44 and is disposed at the side edge of the opening 40.

A mask 50 having two apertures is disposed in the first block 44, as shown in FIG. 6, and one end of each light guide member 42 and 46 is fitted into each aperture of the mask.

One end portions of the two light guide members 42 and 43 are arranged side by side in the film moving direction, and the distance t between the one end surfaces of the two light guide members is slightly shorter than the length of the mark or the image of the mark on the film to be used. ing.

The other end of the light guide member 42,45 is inserted into the through hole 451,452 of the second block 450 on the substrate 41. As shown in FIG. 7, a filter 51 is disposed on the end face of the light guide member ji 42 inserted into the hole 451 of the second block 45, and the optical signal transmitted by the light guide member 42 passes through the filter 51 and passes through the first is sent to the photoelectric conversion member 52 of. The other light guide members 43 similarly transmit optical signals to the second photoelectric conversion member through filters similar to the filter 51. The output terminal of each photoelectric conversion member is connected to a printed board 53.

Each filter controls the amount of light transmitted by each light guide member, corrects for differences in the amount of light transmitted due to variations in the diameter of the light guide member, and differences in the characteristics of the photoelectric conversion member, so that the amount of light incident on the light guide member is constant. In this case, a constant output voltage is obtained from the photoelectric conversion member of each mark detector.

When the mark detector 21 is mounted at a predetermined position on the support base 55, the printed board 53 is inserted into the connector 56 and connected to the main circuit of the apparatus. When the film drive motor is driven by the search command to move the film, the light beams of the lamp 25 entering the light guide members 42 and 45 are blocked by the marks (opaque), so that the light beams are directed to the light guide parts 42 and 46, respectively. A signal is generated, and this optical signal is sent to the first and second photoelectric conversion members through filters, respectively, and converted into an electrical signal. A photodiode, a phototransistor, etc. are used as the photoelectric conversion member.

8 to 10 show other embodiments of the optical member. FIG. 8 shows an optical member consisting of a Fresnel lens 125, and FIG. 9 shows a reflective film around the periphery except for the upper and lower end surfaces. The light incident surface of the glass rod 225 is formed in a plane perpendicular to the incident light, the light exit surface is formed in a plane parallel to the film surface, and the light exit surface is formed in a plane parallel to the film surface. The emitted light hits the film surface perpendicularly.

The light exit plane is arranged opposite to the mark detector.

FIG. 10 shows an optical member consisting of an optical fiber bundle opening 25. As shown in FIG. Note that when an optical fiber bundle is used, one end of the optical fiber bundle is provided at a fixed position facing the condenser lens, and the other end is configured to be moved in conjunction with the movement of the mark detector.

By making the area of the light exit surface of the optical member 225° 625 smaller than the area of the light entrance surface, the amount of light irradiated by the mark can be further increased.

Alternatively, a lens having a focal length that matches the angle of the incident light beam may be used as the optical member so that the emitted light is incident perpendicularly to the film surface.

In the above embodiment, the light from the mark is received by the photoelectric conversion member via the light guide member, but the light from the mark may be directly received by the photoelectric conversion member.
1' As described above, according to the present invention, when an image area and a mark on a recording medium are illuminated by the same light source, the amount of illumination light for the mark recorded on the side edge of the image area is increased to efficiently illuminate the mark. 5. As a result, the mark can be reliably detected regardless of the mark's placement position, and erroneous searches can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of main parts of a conventional search device, Fig. 2 is a block diagram of a film reader to which the present invention is applied, Fig. 6 is a block diagram of an illumination section, Fig. 184 is a diagram explaining a prism, and Fig. The figure is a perspective view of the mark detector, FIG. 6 is a sectional view of the first block, FIG. 7 is a sectional view of the second block, and FIGS. 8 to 10 are configuration diagrams showing other embodiments of the optical member. It is. 14...Lamp 15...Condensing lens 21...Mark detector

Claims (1)

Scope of Claims: (1) A device for searching for a desired image by detecting a mark on a recording medium having an image and a mark provided on the side of the image, which includes a light source that illuminates the recording medium; An optical lens, an optical member disposed between the condensing lens and the recording medium and emitting light in a direction different from the direction of the incident light, and a means for moving the optical member in conjunction with mark detection means. Search device. (2) The search device according to claim 1, wherein the optical member has a light exit surface parallel to the surface of the recording medium. (5) The search device according to claim 1, wherein the optical member is made of a member that refracts light.