JPS5848173A - Information retrieval device - Google Patents

Abstract

PURPOSE:To improve operability by giving an alarm while inhibiting a film from moving even if a key for moving back the film by one information frame group or one frame is pressed during the retrieval of the 1st information frame with a subject mark or during reset mark detection. CONSTITUTION:A microfilm 1 consists of plural information frames K1, K2- Kn, and each frame has a frame mark MK. When plural frames KG form one pieces of information, the starting frame has a subject mark Mcn. End parts are connected to leader tapes 1a and 1b with a start mark MS and an end mark M. A key at the input part of the retrieval device which is not shown in the figure is operated to access a desired information frame Ki, thereby projecting its information on a screen. In this case, even if operation for moving back the film by one group or one information frame is performed after during the retrieval of the 1st subject mark Mcl or after a reset mark (start mark) is detected, the film is not moved and a warning of the erroneous operation is generated. Thus, the operability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information retrieval device such as a reader printer that can perform frame retrieval for each information frame of microfilm and retrieval for every six information frame groups.

Such an information retrieval device uses, for example, a negative or positive microfilm as shown in FIG. 1 (a) or (b).

This microfilm 1 consists of a starting end leader tape 1a that is held on a take-up reel (not shown), and a terminal end leader tape 1b'1 that is held on a reel in a cart v-zip:
A black no start mark (which becomes a reset mark when returning) and an end mark MBY are attached to the connected parts.

A large number of information frames K, in which information is photographed and recorded at regular intervals, are arranged on the film 1 between both markers, and a frame mark MK is attached corresponding to each information frame. A group of information pieces (generally consisting of multiple or several pieces, but
(In some cases, one piece of information corresponds to one piece of information.) A case mark Mc is attached corresponding to the first frame of KG.

Then, the information retrieval device detects the frame mark MK- and the subject mark Mc on this microfilm 1, and performs a frame search (l).
It is possible to perform a search for each frame and an item search (a search for each group of information frames for one item).

In other words, send information piece K by 1 frame + 1 piece key, 71 piece key to move back 1 piece, send 41 pieces of information piece group KG + 1 piece key, 1
Keys for going back by item, numeric keypad for entering the piece number or item number you want to automatically search.

Equipped with a search key to start an automatic search, a changeover switch for piece search and item search, a counter and a display to display the count value, etc. In the piece search mode, the counter changes to the piece mark M.
Count K and display the piece number on the display, and in case search mode ℃ count the counter or case mark Mc and display it on the display.And in either mode, advance and return one frame, and display one item. In addition to being able to forward and return, it is also possible to automatically search by setting the piece number in the piece search mode and the piece number in the item search mode using the ten keys in advance.

By the way, when the first information piece with a subject mark (1 in Figure 1 (a) and 1 in (b)) is being searched,
Since it is not possible to return any more information frame groups, it is an erroneous operation when the 11 item key is operated to return the information frame group KG by one item in this state.

However, in such a case, conventional information retrieval devices of this type either do nothing or return the microfilm and stop until the reset mark (start mark Ms, when returning the film) is detected. ,
The operator sometimes wastes time without paying attention to erroneous operations.

This invention was made to solve this problem, and as mentioned above, when the -1 item key is operated while the first item marked information piece is being searched, the key operation is The first step is to improve operability by disabling the microfilm and prohibiting the movement of the microfilm, as well as issuing a warning to inform the operator that an incorrect operation has occurred.
The purpose of

As shown in FIG. 1 (B), the first information piece with a subject mark has an information piece without a subject mark MC in front of 4 (K, ...,
), it is necessary to be able to go back one frame at a time even if 4 is being searched for the first information frame with an item mark in item search mode, so press the -1 frame key. [Enables the function without issuing an alarm even if the function is operated.]

However, if the 11th frame key is operated after 1 is searched for the 1st frame, the machine will return to the reset mark (M8) and stop.If the 11th frame key is operated again after that, it will be a J error operation and a warning will be issued. Since this is desirable, the second purpose is to do so.

Therefore, the information retrieval device according to the first invention includes a first item marked frame detection means for detecting when the first item marked information frame of the microfilm is being searched; An erroneous operation determination means outputs an erroneous operation signal and prohibits movement of the microfilm when the information frame group return key is operated while the frame detection means is outputting a detection signal, and the erroneous operation determination means detects an erroneous operation. The first object of the present invention is achieved by providing an erroneous operation warning means that issues a warning when a signal is output.

Furthermore, a second invention provides that the erroneous operation determination circuit is
The second object is also achieved by outputting an erroneous operation signal even when a key for moving the information frame back one frame is operated while a reset mark is being detected.

Below 1. This invention will be described in detail with reference to FIG. 2 and subsequent figures of the accompanying drawings.

FIG. 2 shows the external appearance of the main body of the league printer, which is an information retrieval device embodying the present invention, in which 2 is a screen, 6 is a film drive unit for searching microfilm, 4 is an operation panel, and 5 is a copy tray. .

The operation panel 4 is provided with various switches, keys, dials, lamps, etc., as shown in FIG.

7 is a power switch to turn on and off all the power sources of the machine, 8 is a print switch to perform copying operations, 9 is a paper end lamp that lights up when the photosensitive paper runs out, and 10.11 is a copy switch. 12 is a toner lamp that lights up when toner runs out, and 16 is a solvent lamp that lights up when there is no solvent.

14 is the 11-frame key to advance 1 kl of microfilm frames, 15 is the 11-frame key to go back 1 frame, and 16 is the search finger to search by film number! 17 is a stop key for stopping film movement and copying; 18 is a clear key for clearing the numbers displayed on the number display 27;

19 is a preset key for presetting a number entered in a register using the numeric keypad 2o to a frame or kakunta in the internal RAM of the microcomputer, which will be described later, and 21 is a rewind key for rewinding the film. -, 22 is a +1 item key for advancing the film by one item, 23 is an 11 item key for returning one item, and 24 is a manual dial for manually advancing and returning the film.

25 is a copy density tire that adjusts the copy density to 1;
26 is the number dial for setting the number of copies (this dial does not work at the moment of copying), 27 is the 4-digit 7
A numeric display consisting of segment LEDs, 28 is a search switch used when switching from piece search mode to item search mode, 29 is a item copy switch, and when copying items, turn on this switch and turn on print switch 8. do.

Next, a mechanism for projecting film and making copies by this reader printer will be explained with reference to FIG.

The information frame of the microfilm 1 held down by the pressure plate 62 on the film guide 61 is irradiated with light from the lamp 64 that passes through the condenser lens 65, passes through the projection lens 36, is reflected on the first mirror 67, and is reflected on the second mirror. 6
8 onto the screen 2. This is the state in which a normal microfilm 1 is inserted and is being projected.

Now, if the print switch 8 in FIG. 6 is pressed, the drive motor (not shown) of the photosensitive paper conveyance system starts to rotate, and at the same time the mirror clutch 41 is turned on, the mirror cam 42 rotates, and the second mirror 68 is turned on. Move to the position indicated by the imaginary line. And after moving, Mirror Clara 7
41 is turned off. During this time, the roll of photosensitive paper 40 is started and cut into a certain length by a cutter 46.
Charged by the charging section 44, the vacuum belt 4
5 reaches the exposure surface 46.

Furthermore, when the print switch 8 is pressed, the lamp 64 that was irradiating the microfilm 1 at this point is turned off. Then, when the photosensitive paper 40 reaches the exposure surface 46, it is temporarily stopped, and the lamp 64 is turned on again to perform static exposure.

When the exposure for a certain period of time is completed, the photosensitive paper 40 is turned off and the photosensitive paper 40 is moved again toward the developing section 47. The photosensitive paper 40 that has entered the developing section 47 is developed with a developer, and then transferred to the drying section 4.
It is dried in step 8 and transported to a copy receiver. Further, when the exposure is completed, the mirror clutch 41 is turned on, and the second mirror 68 also returns to its original position.

Note that 49 is a reflecting plate that reflects the light emitted by the lamp 64 toward the condenser lens 65.

Next, the film drive unit will be explained with reference to FIG.

A microfilm 1 is stored in a roll 51 within a cassette 50. Insert the cassette 50 into the opening, and press the search key 16. +1 piece key 14. +1 key? 2. By operating the feed direction of the manual dial 24, the solenoid 52 is turned on, the thread roller 56 moves toward the film surface, and at the same time, the drive motor 54 rotates.

The drive motor 54 rotates at low and medium speeds.

There are three speed levels. A detailed explanation of this speed will be given later.

In the above case, the film is fed at medium speed. Film 1 scraped out from inside the cassette 50 by the thread roller 56
enters between the drive roller 55 and the press roller 56.

When the film 1 is inserted between both ends -255°56, the capstan switch (hereinafter referred to as rCAP switch) is activated.
57 turns on. - By turning on this C, AP switch 57, the solenoid 52
is removed, and the film feeding force is controlled by the drive roller 55.
It will be given from Then, the film 4 passes through the film gate 58 and is wound around the reel 59. 60 is a film holding arm.

Then, when the start mark is read by the mark detector described later, it will be either medium to high speed (search key when searching for the 20th frame or later) or low speed (, +1 frame key, +1 frame key).
item key, search key when searching for pieces within 19 pieces). Thereafter, when the mark detector detects a predetermined mark, the advance of the film 1 is stopped and the lamp 64 is turned on to project the stopped frame.
The mark detection section is constructed as shown in FIG.

Soshiso, lamp drying 4. The piece mark MK and the subject mark Mc on the microfilm 1 illuminated by the light of the mirror 61.6
2, is magnified (doubled) by lenses 63 and 64, is reflected by mirrors 65 and 66, and reaches a piece mark detector 67 and a piece mark detector 68. Note that the information on that piece is projected onto the screen 2 in FIG. 4 through a projection lens 66.

As shown in FIG. 7, the piece mark detector 67 is
, A2. Equipped with Bl, B2, and mark detector 68
is equipped with sensors A,,B,. Each sensor is specifically a photodiode.

The piece mark detector 67 also serves as a start mark detector and an end mark detector, and the piece mark detector A1. B1 creates a piece mark borrowed name for piece mark counting, and sensor A
A start mark signal, an end mark signal, and a reset mark signal (when the microfilm is fed in the return direction and a start mark is detected) are generated by 2, 82 and Alt B. Sensors A 3 and B of the target mark detector 68
, 3 produce the subject mark signal.

Note that the microfilm 1 shown in FIG. 1 is used.

FIG. 8 shows a film drive circuit and its input and output signals. The direction is controlled and the solenoid 520 is turned on and off in a controlled manner.

Table 1 shows the relationship between the 700 Å force signal of this film drive circuit and the film advancing direction and speed.

Each input signal in FIG. 8 of Table 1 and the above Table 1 is as follows. Note that the film was not fed under the conditions marked * in Table 1.

GO: High speed signal MID: Medium speed signal DOWN: Low speed signal REw: Return signal M8TP, signal to stop the motor when using the manual dial.

CAPSW: CAP switch 570 on/off signal,
It turns on when the film is wedged between the drive roller 55 and press roller 56 in FIG.

MDS: When the manual dial is moved, a signal that changes the motor rotation speed according to the position of the dial.

On the other hand, the direction signal DS in the output signal is "111" in the forward direction, and "o1" in the return direction.

FIG. 9 shows the print control circuit.

When the print switch 8 shown in FIG. 6 is turned on by this print control circuit 80, the motor 81 (M2') for transporting the photosensitive paper is started, and the various parts shown in FIG. A copy of the existing information piece is made and ejected to the copy receiver 5.

The mirror clutch OFF signal, lamp ON signal, and reprint signal are signals inputted from the search control circuit shown in FIG. ,! K, next. pieces. 3. Yes, the print switch is input instead of being operated.

FIG. 10 is a diagram showing the relationship between the search control circuit and its turnout signal in this embodiment.

This search control circuit 9o includes a central processing unit (CPU), a ROM as a program memory, and an RA of data memory including a counter and a register.
A one-chip microcomputer with M etc. is used.

In the input system, on/off signals from each operation key or switch of the operation panel 4 shown in FIG. 3 are input. The manual switch 91 is a switch that is turned on when the manual dial 24 shown in FIG. 6 is rotated.

The ninth frame switch 92 is a switch inside the machine, and is a frame number selection switch that changes the film speed from high speed to low speed during retrieval. The search control circuit 90
When the frame switch 92 is off, the speed is switched to low speed before 19 frames, and when it is on, the speed is switched to low speed before 9 frames.

However, even if this 9th frame switch 92 is off, when the item search switch 28 is on, the switch is set before the 9th frame.
Signals from both switches are inputted via an R gate 96.

1. A direction signal DS indicating the feeding direction of the microfilm and a direction signal CA indicating whether or not the microfilm is loaded are sent from the film drive circuit 70 shown in FIG.
An on/off signal of the P switch is input.

Furthermore, from the print control circuit 80 shown in FIG. 9, a paper stop signal FAT, which is output when the exposed surface of the photosensitive paper has stopped, and a print signal P, which is output when the print switch is turned on, are input.

However, the print signal P is inputted via an AND gate 94 that performs AND with the output of the copy switch 29 so that it is input only when the copy switch 29 is on.

In addition, sensors AX, Bl, A2 . of the piece mark detector 67 shown in FIGS. 6 and 7. The output signals of sensors A, , B of the mark detector 68 are input to the mark preprocessing circuit 95 to discriminate each mark, and the start mark signal, end mark signal, and reset mark signal (microfilm A start mark detection signal), a piece mark signal, and a subject mark signal are output when the signal is sent in the backward direction, and input into the search control circuit 90.

The position switch 96 is a switch that is turned on when the loaded microfilm is positive and turned off when it is negative.

As for the output system, as each film drive related output to the film drive circuit 70 in FIG.
, Go (high speed), DOWN (low speed).

RBW (return), M8TP (motor stopped during manual)
output each signal.

Also, a mirror clutch OFF signal and a lamp ON signal are sent to the print control circuit 80 in FIG.

Outputs a reprint signal.

If the operator makes an erroneous operation, an erroneous operation signal 5Ml5S is output and a buzzer 97 sounds to warn the operator.

Also, in the piece search mode, piece number data is output, and in the item search mode, item number data (counted value by a counter in RAM or input value by a numeric keypad) is output, and decoded by a decoder 98 to produce 7 segments), , L It is displayed on the 4-digit numerical display 27 by ED. In this case, each digit of the numeric display 27 is dynamically displayed in sequence according to the switching signal SC.

Next, during the operation of the search control circuit shown in FIG.
This will be explained with reference to the operational flowchart shown in the figure.

Figure M11 shows an outline of the main routine, which starts from the start when the power switch 7 in Figure 6 is turned on.

First, a check is made to see if the search switch 28 is on, and if it is NO, it is a piece search top mode, so the force and counter are operated as a piece counter.

If YES, it is the case search mode, so the counter operates as a case counter.

Next, check whether the numeric keypad 20 is on and press Y
If it is B2, the program jumps to the digit routine and sets the digits in the registers one after another.

If the numeric keypad 20 is not operated, then the +1 piece key 14. -1 piece key 15. +1 item key 22° -1 item key 2
3. Check the search keys 16 in sequence, and if any of them is operated and turned on, press + to perform the warping process.
1゛ piece routine, -1 piece routine, +1 case, -chin S
-Proceeds to either the one item routine or the search routine, but
When proceeding to the -1 frame routine and -1 item routine, the mistake check routine according to the present invention is passed.

In addition, manual routine and rewind routine.

The copy routine etc. is shown in Figure 1. The illustration is omitted.

In the mistake check 1 routine that is passed when the -1 item key is on, as shown in Figure 12, it is first checked to see if the count value of the counter is rlJ, and if it is not "1", the main routine in Figure 11 is performed. The process returns to step 1 and proceeds to the -1 case routine to perform processing to return the information frame group by one case.

When the count value of the cursor is rlJ, the next item search switch is checked to see if it is on, and if it is not on, the process proceeds to the item 11 routine as described above, and if it is on, the next item mark is detected. Check to see if there are any.

When the subject mark is not detected, for example, 2 or 3 is being searched for in the information frame in Figure 1 (a),
Since 1 is not retrieved in the first information frame with a matter mark, the process returns to the main routine, proceeds to the -1 matter routine, and returns the microfilm 1 until the matter mark Mc is detected.

When a subject mark is detected, in the subject search mode, the count value of the counter is set to ``1'' and the information piece with the subject mark MC, that is, the first information frame with a subject mark, is set to 1 (the micro In the case of film, ) is being searched, and the 11 key is turned on in that state, so it is determined that it is an erroneous operation and the erroneous operation signal 8Ml5 is sent.
8 and proceeds to the process of sounding the buzzer 97 to issue a warning.

One device in the search control circuit 90 that performs the above operation corresponds to the first missed piece detection means and the erroneous operation determination means.

Note that the order of checking whether the count value of the r counter is "1", "whether the item search switch is on", and "whether there is an r item mark" may be changed in any manner.

If the operation is determined to be an error, the internal timer is set and started, and the buzzer is turned on to issue a warning until the timer times out. When the timer expires, the buzzer is turned off and the process returns to the start of the main routine shown in Figure 11. . Therefore, no microfilm transfer takes place.

In the mistake check 2 routine that is executed when the 11 frame key is on, as shown in Fig. 13, it is checked whether the reset mark (start mark Ms when returning the film) is detected, and if it is not detected, it is checked. Return to the main routine in Figure 11, proceed to the 11th frame routine,
Processing is performed to move the microphone film back one frame.

If the reset mark is detected, the erroneous operation signal 5Ml
After issuing 5S and issuing a warning by sounding the buzzer 97 in the same manner as described above, the process returns to the start of the main routine shown in FIG.

Therefore, in the phycrofilm shown in Figure 1 (middle) K, even after 4 is searched for in the first item-marked piece,
- The operation of the 1-frame key is valid. - Each time you turn it on, you can move back one frame at a time. After the reset mark MS is detected, the operation of the -1 frame key is disabled, the film does not move, and an erroneous operation warning is issued.

Note that the erroneous operation warning means is not limited to a buzzer, but may also be a visual warning means such as a lamp or a single figure, or an audio warning means using a voice synthesizer or the like.
-Next, another embodiment of the present invention will be described with reference to FIG. 14, in which the first marked piece detection means and the erroneous operation determination means are provided outside the search control circuit.

The 10th counter is a counter as a mark counting means, and counts the piece mark signal (when the 8 item search switch 28 is off) or the item mark signal (when the item search switch 28 is on) that is input via the switching circuit 101. do. However, when the film is returned in the case search mode, the countdown starts at the fall of the case mark signal.

Reference numeral 102 denotes a first item marked piece detection means, which checks the count value of the counter 100 and outputs 111 only when it is "1", a counter check circuit 105), the output of this counter check circuit, and the item search switch 28. on/off
It consists of an AND circuit 104 which takes an AND of an off signal (11" when on, 10" when off) and a subject mark signal (becomes 111 when a subject mark is detected).

Therefore, if the count value of the counter 100 is "1", the item search switch 28 is turned on, and the item mark is detected, the output of the AND circuit 104, that is, the first item marked piece detecting means 102 The output becomes 11'', indicating that the first information frame with the item mark has been retrieved.

Reference numeral 105 denotes an erroneous operation determination means, which outputs the output of the AND circuit 104 and the operation signal of the 11 key 26 (when operated,
The AND circuit 106 takes an AND with the -1 frame key 15 operation signal (which becomes 111 when operated) and the reset mark signal (11 when the reset mark is detected).
1), and an OR circuit 108 which takes the OR of each output of this AND circuit 106 and the AND circuit 107.

Therefore, if the 11 item key 26 is operated while the first item marked information frame is being searched, the AND circuit 10
The output of 6 becomes 111, and the output of the OR circuit 108, that is, the output of the erroneous operation determination means 105 also becomes ``1'', which is output as an erroneous operation signal S MI ssh, which is input to the search control circuit to inhibit the movement of the film. At the same time, the timer circuit 109 is triggered. As a result, the timer circuit 109 outputs a high level output for a certain period of time, turns on the transistor 110, operates the buzzer 97, and issues a warning.

On the other hand, when the -1 frame key 15 is operated, the function remains valid until the reset mark is detected and the erroneous operation signal 8Ml88 is not output, but if the -1 frame key 15 is operated after the reset mark is detected. Then, A, ND
The output of 107 becomes 111, and the output of OR circuit 108 also becomes 11#, and the erroneous operation-discriminating means 105 outputs the erroneous operation signal 8Ml8B, so the movement of the film is prohibited and the buzzer operates for a certain period of time. A warning will be issued.

Note that the erroneous operation determination means in the case of carrying out the first invention is one in which the AND circuit 107 and the OR circuit 108 are omitted.

Furthermore, if the first issue mark on the microfilm is made into a mark that can be identified, the frame detection means with the first issue mark may be a detector that identifies the issue mark.

As described above with respect to the embodiments, the information retrieval device according to the first invention is configured such that when the key to move the information frame group back one group is operated while the first information frame with the item mark is being searched, Since the erroneous operation warning is issued without moving, the operator can immediately notice the erroneous operation and try again, improving operability.

Furthermore, in addition to the above, the information retrieval device according to the invention of the second review also issues an erroneous operation warning without moving the film even when a key is operated to move the information frame back one frame after a reset mark has been detected. Therefore, operability is further improved.

[Brief explanation of drawings]

FIGS. 1A and 1B are explanatory diagrams showing different examples of microfilms used in an information retrieval device to which the present invention is applied. FIG. 2 is a perspective view showing the external appearance of the league printer main body which is an embodiment of the present invention, FIG. 6 is a plan view of the operation panel, and FIG.
The same (a block diagram showing the mechanism for projecting and copying the film, Figure 5 is the same (block diagram of the film drive unit), and Figure 6 is the same (block diagram of the mark detection unit, Figure 7 is a block diagram of the film drive unit). is an explanatory diagram showing the frame mark detector and frame mark detector in Figure 6 in correspondence with the frame mark and frame mark on the microfilm, and Figure 8 is an explanatory diagram showing the relationship between the film drive circuit and its input/output signals. FIG. 9 is an explanatory diagram showing the relationship between the print control circuit and its input/output signals; FIG. 10A is an explanatory diagram showing the relationship between the search control circuit and its input/output signals; FIGS. 16 is an operation flow diagram for explaining the operation related to the present invention by the search control circuit of FIG. 10, and FIG. 14 is a block circuit diagram showing another embodiment of the present invention. 1.・Microfilm K...information, piece MK・
・・Panel mark -Mc・・piece mark MS・・
・Start mark (reset mark) MFX...End mark 2...δ clean 3...Film drive unit 4...Operation panel 5...Copy receiver 7...
Power switch 8...Print switch 14...
+1 piece key 15...-1 piece key 16...Search key 17...Stop key -18...Clear key 19...Preset key 20...Numeric keypad
21...Rewind key 22...+1 item key
23...-1 item key 24...Manual dial
27... Number display 28... Item search switch
29... Copy switch 67... Frame mark detector (also serves as reset mark detector) 68... Mark detector 70... Film drive circuit 80... Flint control circuit 90... Search Control circuit 97...Buzzer (misoperation warning means) 102...First item marked piece detection means 105...
Erroneous operation determination means (Figure 5, Figure 6, Figure 8, Figure 9, Rf) Figure 11 Figure 12 - Procedural amendment (voluntary) July 28, 1981 Haruki Shimada, Commissioner of the Japan Patent Office, Patent application for indication of the incident No. 56-145517 2, Invention name information search device 3, Relationship with the case of the person making the amendment Patent applicant: 1-3-6 Nakamagome, Ota-ku, Tokyo (674) Ricoh Co., Ltd. - 4, Agent 1-20-5 Higashiikebukuro, Toshima-ku, Tokyo 5. Subject of amendment 6. Contents of amendment (1) In the 5th and 6th lines of page 20 of the specification, the ``numeric position'' is corrected to read ``r'' as numeric value j. (2) - Replace "Figure 12" and "Figure 16" of the drawings with the corrected drawings attached to this document. 7. Attached documents Corrected drawings ("Figure 12", "Figure 16") 1 copy Figure 12 Figure 13

Claims (1)

[Claims] 1. Detecting a frame mark attached to each information frame of a microfilm or an issue mark attached to the first frame of a group of information frames recording one item of information. In the information retrieval device that searches for a desired information frame or group of information frames on the microfilm, when the first item-marked information frame on the microfilm is being searched, the first item-marked frame is detected. An erroneous operation that outputs an erroneous operation signal and prohibits movement of the microfilm when the information frame group 'Y1 group return key is operated while the detection means and the first marked frame detection means are outputting a detection signal. An information retrieval device comprising: a determining means; and an erroneous operation warning means for issuing a warning when the erroneous operation determining means outputs an erroneous operation signal. 2. By detecting the frame mark attached to each information frame of the microfilm or the index mark attached corresponding to the first frame of a group of information frames in which one piece of information is recorded, the microfilm is In the above information retrieval device for searching for a desired information piece or group of information pieces. A first item marked frame detection means detects when the first item marked information frame of the microfilm is being searched, and a first item marked frame detection means detects the information when the first item marked information frame is outputting a detection signal. An erroneous operation signal is output when the key to return one group of frames is operated, and when the key to return the information frame by one frame is operated while the reset mark provided near the beginning of the microfilm is detected. What is claimed is: 1. An information retrieval device comprising: erroneous operation discriminating means for prohibiting the movement of the microfilm; and erroneous operation warning means for issuing a warning when the erroneous operation discriminating means outputs an erroneous operation signal.