JPH0786638B2 - Information retrieval method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention detects a mark on an information recording medium such as a microfilm and counts the mark to retrieve desired information in the information recording medium. Regarding

(Prior Art) Conventionally, a search device incorporated in a film reader or the like uses a film having a search mark on the side of each frame of the film, optically detects this mark, and counts it. As a result, a desired frame in the film is automatically searched.

The above search method illuminates the mark on the film with a lamp,
When the film is transferred, the change in the light blocked by the mark is detected by the mark detector, the output signal of this mark detector is counted by the counter, and the counting contents of this counter and the keyboard etc. are input. The comparison circuit compares the frame number of the desired image frame, and when the two match, the comparison circuit issues a stop signal to the drive control circuit to stop the drive system that transfers the film and place the desired frame on the screen. It is made to stand still at a predetermined position where it is projected.

As described above, in the search method, the search is performed by counting the output signal of the mark detector with a counter, and this counter, for example, a micro computer or the like, has a limit in the counting speed, and thus the mark interval is small. The film feeding speed is controlled so that counting can be performed even when the film is short (image frames are adjacent to each other). Hereinafter, this speed is referred to as a counting speed (first speed).

(Problems to be solved by the invention) By the way, according to the conventional search method, even if the mark interval is very long (a certain image frame and the next image frame are separated), the film feeding speed is originally Despite the fact that there is no problem even if the mark-free portion is fed at the counting speed or higher, the feeding is performed at the counting speed. Therefore, when searching for a film in which image frames are separated as described above, there is a problem that the search speed decreases.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional example, and its purpose is to increase the feeding speed for a portion where the mark interval is long and to separate the image frames. An object of the present invention is to provide an information search method that prevents a decrease in search speed even with existing information recording media.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, it is desirable to detect the marks attached to each information of the information recording medium and count the detected marks. In the retrieval method for retrieving information, the mark interval is measured while the information recording medium is being fed at the first speed, and if the mark is not detected for a predetermined period after the mark is detected, the information recording medium is faster than the first speed. The feeding speed of the information recording medium is controlled according to the mark interval so that the feeding is performed at the second speed, and when the mark is detected during the feeding at the second speed, the feeding is performed at the first speed according to the interval of the marks. Characterize.

(Operation) In the present invention, the distance between the marks is measured while the information recording medium is being fed at the first speed, and when the mark is not detected for a predetermined period after the mark is detected, the information recording medium is operated at a speed higher than the first speed. The recording medium is fed at the second speed, and when the mark is detected during the feeding at the second speed, the feeding speed of the information recording medium is controlled according to the interval of the marks so as to feed at the first speed. The feeding speed of the information recording medium can be changed depending on the interval.

(Example) Below, this invention is demonstrated based on the Example shown in figure. First
The figure shows a microfilm reader equipped with an information retrieval device to which the present invention is applied. In the figure, 1 is a supply reel, 2 and 3 are guide rollers, and 4 is a microfilm F as an information recording medium. Lamps, 5 is a condenser lens, 6 and 7 are glass plates placed opposite to each other across the film transfer passage, 8 is a capstan roller, 9 is a pinch roller, and 10
Is a take-up reel. The supply reel 1 and the take-up reel 10 are connected to a mild tension and take-up motor, and the capstan roller 8 is connected to a film drive motor.

The microfilm F is stretched between the supply reel 1 and the take-up reel 10 and is wound on the take-up reel or rewound to the supply reel by driving the capstan roller 8.

11 is a mark detector, 12 is a projection lens, and 13 is a screen.

As shown in FIG. 2, the microfilm F has a frame 15 on which an image is recorded and a mark 16 attached to the side edge of each frame 15 and having a different density from the periphery (base portion). The frame 15 and the mark 16 as information on the film F are illuminated by the light of the lamp 4 when passing between the glass plates 6 and 7, and the image of the illuminated frame is projected on the screen 13. In this embodiment, the base portion B of the film F is transparent and the mark 16 is opaque, but the base portion B is opaque.
A transparent mark 16 can also be used. The mark detector (photoelectric conversion means) 11 comprises an optical fiber 20 and a photoelectric conversion element 21 as shown in FIG.
The front end of 20 is provided opposite to the passage through which the mark 16 and the base portion B pass, and the rear end thereof is provided opposite to the photoelectric conversion element 21.
The photoelectric conversion element 21 receives the light from the lamp 4 that has passed through the film F via the optical fiber 20. Here, when the film F is transferred in the arrow direction, the light incident on the photoelectric conversion element 21 is interrupted by the base portion B and the mark 16.

On the other hand, 30 is a mark sensor, which is arranged upstream of the mark detector 11 in the feeding direction of the film F as shown in FIG. 1. In the case of this embodiment, a small photo interrupter is provided. However, functionally, the optical fiber 20 and the photoelectric conversion element 21 in FIG. 2 are used.
Is the same as. That is, when the mark 16 passes through the mark sensor 30, the mark sensor 30 outputs a rectangular wave signal.

Next, the control system of this embodiment will be described with reference to the block diagram shown in FIG. 30 is the mark sensor in FIG.
When the rectangular wave is transmitted by the mark sensor 30 at 32,
Shows the timer part that keeps the output high level for a certain period of time from the last rise of the input rectangular wave.This timer part is for measuring the mark interval on the film, and when the mark interval is more than the set length. Outputs a low level signal and outputs a high level signal when the length is shorter than a set length. In this embodiment, a retriggerable one-shot circuit is used. 34 is a motor driver, FA
It has a speed switching function to select ST / SLOW. 3
A capstan drive motor 6 drives the capstan roller 8. In addition, the motor driver 34, when the output signal of the timer unit 32 is low level, the film F
If the feeding speed is higher than the counting speed (first speed), which is the maximum speed that enables counting even when the interval between the marks 16 is short, and is at a high level , Capstan drive motor to count speed
It controls 36.

Here, the operation will be described assuming that the film F is fed in the direction of the arrow in FIG. 1, and the timer unit 32 normally feeds the film F to the motor driver 34 at a speed equal to or higher than the counting speed. Although the control signal is transmitted as described above, when a rectangular wave output signal is transmitted by the mark sensor 30, that is, when the mark 16 on the film F in FIG. A signal is sent to the time motor driver 34 so that the film F reaches the counting speed. This state is shown in FIG. 4 as the output signal Ps of the mark sensor 30, the output signal Pt of the timer unit 32 and the feeding speed of the film F, and the t _w of the output signal Pt of the timer unit 32 is the timer unit 32 of FIG. The pulse width of the one-shot circuit of the mark sensor
The pulses of the output signal Ps of 30 are those emitted by the mark 16. Then, the output signal Pt of the timer unit 32 is
Since the timer unit 32 uses a retriggerable one-shot circuit inside, the marks 16 are continuously marked by the mark sensor.
It is maintained at the high level for the time detected by 30, and becomes the low level if the output signal Ps of the mark sensor 30 is not sent within the time t _w . In addition, the output signal Pt of the timer unit 32
Becomes the FAST / SLOW switching signal of the motor driver 34 as described above, and the feeding speed of the film F changes as shown in FIG.

Thus, with the above-described structure, while searching for a portion on the film F where the information frame 15 does not exist, the film F is fed at a speed higher than the counting speed, and the portion of the mark sensor 30 is fed. When the mark 16 passes through, the feeding speed of the film F is decelerated, and when the mark 16 reaches the mark detector 11, the feeding speed of the film F becomes the counting speed. Here, the mark sensor 30 in FIG. 1 needs to be arranged upstream of the mark detector 11 in the feeding direction of the film F so that the above-mentioned deceleration can be performed. It is also possible to eliminate the mark detector 11 and count the marks by the output pulse of the mark sensor 30.

(Effects of the Invention) The present invention measures the distance between marks during feeding of an information recording medium at a first speed, and if the mark is not detected for a predetermined period after detecting the mark, the information recording medium is faster than the first speed. In order to control the feeding speed of the information recording medium according to the interval of the marks so that the marks are detected at the second speed and the marks are detected during the feeding at the second speed. The first speed is the feeding speed at which the marks can be detected and counted even when the marks on the information recording medium are short, and the normal first speed when the marks are not detected for a predetermined period after the marks are detected. The information recording medium can be fed at a higher second speed so that the marks can be detected and counted, and the information recording medium corresponding to the mark interval can be fed, so that the search operation can be efficiently performed. .

[Brief description of drawings]

FIG. 1 is a schematic view showing a microfilm reader equipped with an information search device to which the present invention is applied, FIG. 2 is a schematic perspective view showing a mark reading state in FIG. 1, and FIG. 3 is an information search according to the present invention. FIG. 4 is a block diagram showing an embodiment of the control system of the apparatus, and FIG. 4 is a time chart of the output signal of each part in FIG. Explanation of code 16 …… Mark F …… Micro film (information recording medium) 15 …… Frame (information)

Claims (1)

[Claims] 1. A search method for detecting desired marks by detecting marks attached to each information of the information recording medium and counting the detected marks, wherein the information recording medium is fed at a first speed. The mark interval is measured, and when the mark is not detected for a predetermined period after the mark is detected, the information recording medium is fed at a second speed higher than the first speed, and the mark is detected during the feeding at the second speed. Then the first
An information retrieval method, characterized in that the feeding speed of an information recording medium is controlled in accordance with the interval of marks so that the information is fed at a speed.