JPH0792590B2 - Information retrieval device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information retrieval apparatus for retrieving a desired microimage from a plurality of microimages printed on a microfilm. The present invention relates to an information retrieval device capable of providing size information of a micro image to a micro film printer or the like formed on recording paper.

[Conventional technology]

The following microfilm printers are known.

That is, an image size sensor consisting of a large number of photosensors having a width substantially equal to the width of the image is removably provided in the image forming optical path from the micro image on the microfilm to the photosensitive member. In the state of being located inside, the width of the micro image is obtained from the number of photosensors that detect light, and the recording paper suitable for the image size is supplied to the transfer device (see, for example, Japanese Patent Laid-Open Publication No. Sho. 59-30550).

[Problems to be solved by the invention]

However, in the case of the above-described conventional configuration, there is a problem as described below, and there is room for improvement.

That is, since a plurality of photosensors for covering the width of the micro image are required as the image size sensor, the larger the micro image to be detected, the more sensors are required, which tends to increase the cost. Further, since the image size is detected based on the number of photosensors that have detected light, the configuration of signal processing for size detection tends to be complicated.

In view of the above situation, an object of the present invention is to search for a micro image on a micro film and detect an image size,
It is to have a simple structure and be inexpensive.

[Means for solving problems]

The information retrieval apparatus according to the present invention comprises a micro image in which a plurality of retrieval marks having a predetermined positional relationship with the micro image are aligned in the width direction of the film and are imprinted in the longitudinal direction of the film in order to retrieve the micro image. An information retrieval apparatus for retrieving a desired micro image from a film, the first sensor detecting a retrieval mark, and the second image detecting a micro image distant from a detection position of the first sensor by a predetermined distance in the longitudinal direction of the film. A sensor, a control means for stopping the micro image to be searched at a predetermined position based on the detection result of the first sensor, and a second sensor when the search mark of the micro image to be searched is detected by the first sensor. Microphone to be searched, or the unrecorded part between the micro images is detected. Characterized in that a discriminating means for discriminating the magnitude of the size of the image.

[Work]

That is, in general, a mark for searching a frame of each image is imprinted for each image on the microfilm, and at the time of searching the frame, paying attention to the fact that the mark is detected and counted by a sensor or the like. While effectively utilizing the sensor that detects the mark, at least one other
The size of the micro image can be detected simply by providing two sensors.

That is, the frame search mark is positioned in the upper or lower margin of the leading end portion or the central portion of the image on the microfilm. Therefore, the first sensor for detecting the mark is provided with the second sensor for detecting the non-recorded portion between the images at a predetermined interval corresponding to a certain image size in advance. When the second sensor detects a non-recorded portion when the frame search mark is detected, it is determined that the image size is a preset image size, while the second sensor corresponds to the recorded portion of the image. If no unrecorded portion is detected, it can be determined that the image size is different from the preset image size.

〔Example〕

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

FIG. 1 and FIG. 2 respectively show a front surface and a cross section of a microfilm reader printer as an example of a microfilm printer equipped with an image size detection sensor according to the present invention.

This microfilm reader printer can be switched between a reader mode for enlarging and projecting a micro image on a microfilm (F) onto a screen (5) and a print mode for enlarging and copying on a recording sheet.

In the reader mode, the scan mirror (6) for copying is
It is retracted to the position (x) in the figure outside the projection optical path. Light from the light source (1) below the film (F) passes through the film (F) through the condenser lens system (31), and passes through the lens (30), mirrors (3) and (4) The micro image on (F) is enlarged and projected on the screen (5). Further, in the print mode, the projection mirror (3) is retracted to the position (y) in the figure outside the imaging optical path. The light from the light source (1) is imaged by an imaging device (IF)
Via the scan mirrors (6) and (8) and the fixed mirrors (7) and (9) as an example, slit exposure is performed on the photosensitive drum (19) that is an example of the photoconductor, and the photosensitive drum (19) is uniformly charged. An enlarged electrostatic latent image of the micro image (I) is formed on the formed photosensitive drum (19). The scan mirrors (6) and (8) are connected by a wire (not shown) so as to move integrally.
After moving once to the scan start positions (l) and (p) respectively, the scan is performed toward the scan end positions (n) and (r).

When the print switch (not shown) is pressed in the print mode, the pickup roller (12) or (1
3) rotates, and as will be described later, recording paper of a size corresponding to the size of the micro image on the film (F) is sent out from the paper feeding cassette (10) or (11), and the rollers (14), It is sent to the timing roller (18) by (16) or (15), (16). Timing roller (1
When the recording paper enters into 8), the recording paper detection sensor (17) detects the leading edge of the recording paper and shuts off the transmission to the timing roller (18). At the same time, the scan mirrors (6) and (8) start moving as described above to form a latent image on the photosensitive drum (19). The latent image is transferred onto the recording paper sent from the timing roller (18) in the transfer device (20) in synchronization with the rotation of the photosensitive drum (19) after being developed by attaching toner particles and the like. .
The recording paper after transfer is sent by a carrying device (21), and after the transferred image is fixed by a heating and fixing device (22), it is carried onto a tray (24) by a sending roller (23).

Next, the microfilm (F) loaded in this microfilm reader printer will be described. As shown in FIGS. 3 (a) and 3 (b), the microfilm (F)
Is continuously imprinted on a long film having a width of 16 mm or 35 mm in a mixed form of micro images (I _S ) and (I _L ) of two sizes. These two sizes are
"A3" and "A4" correspond to originals of different sizes. Further, on the microfilm (F), a mark (so-called blip mark) (M) for searching a frame of the image (I) is provided for each microimage (I) in the margin of the film (F). It is imprinted on the part. There are two methods for the position where the mark (M) is imprinted. The first method is the central portion of each image (I) as shown in FIG. 3 (a), and the second method is the tip of each image (I) as shown in FIG. 3 (b). It is a part.

A sensor (S _M ) is provided at a position corresponding to the mark (M) on the microfilm reader / printer side, and as the film (F) is fed, the sensor (S _M ) is marked ( Each time (M) is detected, a counter (not shown) is incremented so that the frame number can be known. Therefore, the micro image (I) in the designated frame can be projected on the screen (5), or the frame number of the image (I) being projected can be known by looking at the counter.

This sensor (S _M ) is also a sensor for positioning the projected image in the reader mode. That is, even if the blip mark (M) is printed by any of the methods described above, the detection of the blip mark (M) by this sensor (S _M ) determines that the frame is the target frame. For example, the feeding of the film (F) is stopped, and at this time, the sensor (S _M ) is arranged so that the image (I) projected on the screen (5) is in a regular position. There is. The position of the sensor ( _SM ) corresponding to the first method is the central part of the screen (5),
The "A3" size micro image (I _L ) is shown in Fig. 4 (a).
In addition, the "A4" size micro image (I _S ) is projected as shown in FIG.
The position of the sensor (S _M ) corresponding to the second method is the leading end of the film (F) in the feeding direction with respect to the screen (5), and the “A3” size micro image (I _L ) is shown in FIG. As shown in (a), and the micro image (I _S ) of "A4" size is projected, as shown in FIG. 4 (c). The blip mark detection sensor (S _M ) is provided at the front of the printer as shown in FIG. 5, corresponding to the two methods of imprinting the blip mark on the microfilm (F) side. The position can be switched to either of the above two positions by the selection switch (2).

On the other hand, the above-mentioned blip mark detection sensor (S _M )
The second sensor (S _B ) that cooperates with the sensor (S _M ) to form the micro image sensor detection sensor (S _I ) is provided as the sensor of (1). The sensor (S _B) detects each image (I) blank section between on microfilm (F) (B). For example, it is a sensor such as a photo sensor. Then, as shown in FIGS. 6A and 6B, the first sensor corresponding to the first system in which the blip mark (M) is imprinted in the central portion of each image (I). When (S _M ) is located at the central portion (a) of the screen (5), the second sensor (S _B ) is located at the position (b) in the figure. In addition, Fig. 6 (c), (d)
As shown in FIG. 2, the first sensor (S _M ) is attached to the film (5) on the screen (5) corresponding to the second method in which the blip mark (M) is imprinted at the beginning of each image (I). If you are located in (F) feed direction leading end portion (c), the second sensor (S _B) is adapted in the position in FIG. (d). Then, when the position of the blip mark detection sensor (S _M ) which is the first sensor is switched by the changeover switch (2) described above, the second sensor (S _B ) also moves relative to the first sensor (S _M ). The position switching is performed at the same time while maintaining the position as described above.

Even in the case of the method shown in FIGS. 6 (a) and 6 (b), or in the method shown in FIGS. 6 (c) and 6 (d), the second sensor (S _B ) is the first sensor respectively. One sensor (S _M ) is provided with a space corresponding to the length of the “A4” size micro image (I _S ) on the film (F) in the longitudinal direction of the film. That is, Fig. 6 (a) and (c)
In case of, the first sensor (S _M ) is the blip mark (M)
And the second sensor (S _B ) detects the non-recorded portion (B) of the film (F), and this micro image (I _S ) is determined to be “A4” size.
On the other hand, in the case of FIG. 6 (b) and (d) a first sensor (S _M) is detected a blip mark (M) but, second
The sensor (S _B ) faces the recording portion of the film (F), and in the case of a negative film, the amount of transmitted light is smaller than that of the non-recording portion (B), so it is not recognized as the non-recording portion,
This micro image (I _L ) is determined to be "A3" size.

The position where the second sensor (S _B ) is provided is the length in the longitudinal direction of the film of the “A3” size micro image (I _L ) on the film (F) with respect to the first sensor (S _M ). The positions (e) and (f) may be located at corresponding intervals. Although not shown, as the second sensor (S _B ),
Two or more sensors may be provided so that three or more types of micro image sizes can be detected.

In the print mode, the pickup roller (12) or (13) for the recording paper feed cassette (10) or (11) corresponding to the size based on the size determination result of the micro image (I) as described above. Is driven to rotate,
The recording paper having an appropriate size is supplied to the transfer device (20).

Therefore, regardless of the size of the micro image (I) on the micro film (F), it is not necessary to specify the copy size one by one when copying the image (I), and the copying operation can be performed efficiently. it can. Moreover, by effectively utilizing the conventional blip mark detecting sensor (S _M ) as the first sensor, for example, if one sensor is provided as the second sensor, it is possible to determine two types of image sizes. Therefore, the signal processing for discrimination can be simplified, and it is advantageous in terms of cost.

In particular, as described above, a single sensor is provided as the second sensor (S _B ) and this sensor (S _B ) is attached to the first sensor (S _M ) on the film (F). When the sensors (S) are provided at positions (e) and (f) at intervals corresponding to the length of the A3 "size micro image (I _L ) in the longitudinal direction of the film, Even when the micro images (I _L ) and (I _S ) are being copied, the second sensor (S _B ) does not have to be moved one by one when copying, because it is outside the image forming optical path, and different image sizes (I _L ),
In the so-called through copy, in which the microfilm (F) containing (I _S ) is continuously copied, the work efficiency can be further improved.

Further, in this micro film reader printer, as described above, in correspondence with the two methods in which the position where the blip mark (M) is imprinted is different, the smaller size micro image (I _S ) screen ( 5) The projection position above is different. That is, as shown in FIG. 4 (b), the target micro image (I _S ) is projected on the central portion of the screen (5), and as shown in FIG. 4 (c), the screen (5) ), The target micro image (I _S ) and the next frame micro image (I _S ′) may be projected. Therefore, when copying the projected micro image in cooperation with the blip mark selection switch (2) described above, the target micro image (I _S ) is always displayed on the smaller recording paper in any method. It is constructed so that it can be properly copied.

That is, as described above, in the print mode, after the image size is detected, the recording paper suitable for the size is fed to the timing roller (18), and the timing roller (18) temporarily stops rotating there. At this time, the scan mirrors (6), (8) move their scan start positions (l),
The movement starts from (p), and at the same time, the timer (T ₁ ) or (T ₂ ) incorporated in the control device (c) starts to operate. Then, according to the position switching of the image size detection sensor (S ₁ ) corresponding to the two methods of imprinting the blip mark (M), the time required for the scan to reach the preset tip position of each micro image. After waiting for a time corresponding to, the timing roller (18) is rotated to supply the recording paper to the transfer device (20).

The relationship between the set time and the position of each micro image (I) on the screen (5) is shown in FIG.
Further description will be given using the schematic diagram shown in (c). FIG. 7 (a) shows an "A4" size micro image (I) when the blip mark (M) is selected by the selection switch (2) to correspond to the first method in which the blip mark (M) is printed in the center.
_S ) is shown as a copy. After the scan mirror (6) moves from the scan retreat position (x) to the scan start position (l), the scan mirrors (6) and (8) start scanning and the timer (T ₂ ) starts. Screen (5)
The time required for the scan mirrors (6) and (8) to move to the beginning of the "A4" size image (I _S ) projected on the center part of the timer (T ₂ ) time-up setting time (t ₂ ) Further, the imaging start of the photosensitive drum (19) above, time lag between the operation starting timing roller (18) is time-up set time of the timer (T ₅₎ (t ₅₎
Is. Therefore, after (t ₂ + t ₅ ) from the start of scanning, the recording paper is transferred by the timing roller (18) to the transfer device (20).
Then, proper transfer is performed.

If the designated number of copies is one, after the image of the "A4" size micro image (I _S ) is formed on the photosensitive drum (19), the scan mirror (6) moves to the scan retreat position (x). When the designated number of copies is plural, the scan mirrors (6) and (8) are again set to the scan start position (l) after the time (t ₄ ) required for forming an image of “A4” size (I _S ). , (P), the same operation as above is performed, and after the designated number of copies are completed, the scan mirror (6) moves to the scan retreat position (x).

FIG. 7 (b) is a micro image of "A4" size when the blip mark (M) is selected by the selection switch (2) so as to correspond to the second method in which the blip mark (M) is imprinted on the end. (I _S ) shows a copy. At this time, the scan mirrors (6), (8) are moved to the scan start position (l), up to the beginning of the "A4" size image (I _S ) projected on the leading end side of the screen (5) in the film feeding direction.
The time required for moving from (p) is a timer (T ₁₎ time-up set time (t _1), the other operations are the same as those in the case shown in FIG. 7 (b). Therefore, the recording paper is sent to the transfer device (20) after (t ₁ + t ₅ ) from the start of scanning.

Further, FIG. 7C shows copying of a micro image (I _L ) of “A3” size regardless of the method of imprinting the plip mark (M). At this time, exactly the same as the case shown in FIG. 7B except that the time required for forming the image of “A3” size (I _L ) on the photosensitive drum (19) becomes (t ₃ ). By the operation of, the micro image (I _L ) is copied.

The control device (C) for controlling each operation in the above-mentioned copy mode will be described. As shown in FIG. 8, the control device (C) is mainly composed of a microcomputer (MC). The I / O interface (25) to the microcomputer (MC) includes a blip mark selection switch (2), a print switch, a timing roller (18), a recording paper detection sensor (17) in front of the
A scan start position sensor that detects whether the scan mirrors (6) and (8) are at scan start positions (l) and (p), and whether the scan mirror (6) is at the scan retreat position (x). Scan retreat position sensor for detecting the image and micro image size detection sensor (S ₁ )
The signals from the pair of sensors (S _M ) and (S _B ) that compose the are input. Further, from the I / O interface (25), via the drive circuit (26), the scan mirror (6),
A signal for driving (8) in both the forward and reverse directions and a drive control signal for the timing roller (18) are output.

Next, the operation of the microfilm reader printer having the above configuration will be described based on the flowcharts shown in FIGS. 9 to 11.

FIG. 9 is a flowchart showing the overall operation. When the power is turned on, after initial setting (# 1), the reader mode is set, the reader process is performed (# 2), and the state of the print switch is determined (# 3). In the reader processing routine (# 2), as described above, the micro image (I) on the micro film (F) is projected on the screen (5). When the print switch is pressed,
Based on a signal from the state and the image size detection sensor blip mark selection switch (2) (S _1), set the parameters at the time of printing (# 4), Subsequently, a printing process switched to the print mode ( # 5).

The control device (C) of the reader printer has a multi-task monitor, and the multi-task monitor manages a plurality of tasks that divide and divide the operation of the reader printer. The operations of the reader / printer, which are shared by a plurality of tasks, include scanning of a micro image (I), feeding to a transfer device (20), and heating and fixing device (2
2) Temperature control, check of each operation switch, control of exposure, control of toner, detection of paper jam, etc. The multitask monitor manages a plurality of operations as if they were performed in parallel, and each task requires synchronization between operations by means such as checking the flag state. The processing of the case is performed.

Next, among the plurality of tasks described above, a scan task of the micro image (I) and a task of feeding the transfer apparatus (20) will be described.

FIG. 10 is a flowchart of the scan task. In this task, first stop the scan operation (# 1
1). Since the scan mirror (6) is retracted to the scan retreat position (x) in the reader mode, the scan operation is started in the opposite direction to move the scan mirror (6) to the scan start position (l) and The scan mirror (8) is moved to the scan start position (p). When the scan start position sensor (not shown) detects the scan mirrors (6) and (8), the scan operation is stopped (# 12). Subsequently, whether or not the recording paper is fed to the timing roller (18) is determined by the state of the paper READY flag. If the paper READY flag is set to "1" and it is determined that the paper is ready to be fed, the scan operation is started after clearing this flag (#
13).

After that, the built-in timer (T ₁ ) or (T ₂ ) is started according to the set print parameters. That is,
As explained earlier, the image size detection sensor (S ₁ )
Therefore, when it is determined that the size is "A4" and the blip mark (M) is selected by the blip mark selection switch (2) so as to correspond to the first method in which the blip mark (M) is printed in the center, the timer ( Start T ₂ ). Also,
The image size detection sensor (S ₁ ) determines "A4" size, and the blip mark selection switch (2)
When the blip mark (M) is selected to correspond to the second method in which the blip mark (M) is imprinted on the end, and when the image size detection sensor (S ₁ ) determines that the size is “A3”, Start the timer (T ₁ ) (# 1
Four).

When the timer (T ₁ ) or (T ₂ ) times out, it is determined that the scan mirrors (6) and (8) have reached the tip of the micro image (I), and the image formation start flag is set to "1". Stand it up and let the paper feed task know about it (# 15). As a result, the paper feeding task supplies the recording paper to the transfer device (20) as described later.

Subsequently, in accordance with the print parameters, built-in timer (T ₃₎ or (T ₄₎ is to start. That is, the timer (T ₃ ) is started when the image size detection sensor (S ₁ ) determines that the size is "A3" and the timer (T ₄ ) is started when the size is determined as "A4". (# 1
6). Then, the micro image (I) is scanned in a slit shape to form an electrostatic latent image on the photosensitive drum (19), and when the timer (T ₃ ) or (T ₄ ) times up, the image formation is completed. Judgment is made, "1" is set to the image forming end flag, and the paper feeding task is notified of this (# 17).

After that, it is determined whether or not the same micro image needs to be copied, that is, whether or not it is a multi copy (# 1
8). Whether or not the copy is the multi-copy is performed by another task by comparing the counted number of copies with the designated number of copies and determining the state of the flag that changes according to the result. If it is a multi-copy, that is, if it is necessary to continue the copy, the process returns to the step (# 11) and the same operation as described above is repeated. If not multi-copy
That is, if it is unnecessary to continue copying, the scan mirror (6) is continuously moved in the same direction, and the scan retract position sensor (not shown) is used to scan the scan mirror (6).
If is detected, the scan operation is stopped (# 19) and the scan task is ended.

On the other hand, FIG. 11 is a flowchart of the paper feeding task.
In this task, first, according to the size discriminated by the image size detection sensor (S ₁ ), the recording paper of that size is driven by the pickup roller (12) or (13) to the paper feed cassette (10) or One sheet is pulled out from (11) and sent to the timing roller (18) by rollers (14), (16) or (15), (16) (# 21). When the recording paper detection sensor (17) detects the leading edge of the recording paper, it starts a timer (T ₆ ) that is set to time up by the time required to feed the recording paper by the amount necessary to form the lube (# twenty two). After the timer (T ₆ ) times out, the drive of each roller is stopped and the paper RE
Set the ADY flag to "1" to notify the scan task that the paper feed is ready (# 23).

Then, it is determined whether the scan mirrors (6) and (8) have reached the tip portion of the micro image according to the state of the image formation start flag. If "1" is set in the image formation start flag, it is determined that the scanning of the micro image (I) is started, and this flag is cleared (# 24). Then, by adjusting the time lag from the scan start to feed the recording paper, in order to align the image on the front end and the photosensitive drum of the recording paper (19), a timer (T ₅₎ is started, the timer (T ₅₎ After the time elapses, the drive of the timing roller (18) is started and the recording paper is sent to the transfer device (20) (#
twenty five).

After that, the latent image on the photosensitive drum (19) is developed and then transferred onto the recording paper. Meanwhile, whether the image formation is completed or not
It is determined by the state of the image forming end flag, and if "1" is set in this flag, it is judged that the image forming is completed, and this flag is cleared (# 26). Then, as in the previous case, the timer (T ₅ ) for adjusting the time lag is started, and after the timer (T ₅ ) is up, the drive of the timing roller (18) is stopped (# 27).

Similar to the scan task, if it is necessary to determine whether it is multi-copy (# 28) and continue copying, go back to the step (# 21) and repeat the same operation as above to continue copying. If there is, the paper feeding task is ended.

In the above-described embodiment, there are two types of image sizes on the microfilm (F), "A3" size and "A4" size, respectively.
Although it corresponds to the size, the document size corresponding to the image size may be “B4” size and “B5” size, or “A4” size and “B5” size. If three photosensors are used as the second sensor (S _B ) forming the image size detection sensor (S _I ), four types of “A3”, “A4”, “B4”, and “B5” can be obtained. Even if the image size corresponding to the original size is mixed on the microfilm (F), it is possible to discriminate them and supply the recording paper corresponding to the size.

The present invention can be applied to the microfilm printer not having the reader function in addition to the microfilm reader printer described in the above embodiment.

In addition, in the above-mentioned embodiment, the type in which a roll-shaped long film is loaded as the microfilm (F) has been described, but the type in which a microfish type or a type housed in a jacket is loaded The image size detection sensor according to the present invention can also be applied to the above.

〔The invention's effect〕

As described above, in the microfilm printer according to the present invention, the conventional sensor for detecting the frame search mark is effectively used as the first sensor, and in addition to that, the space between the images on the microfilm is separated. Only by providing the sensor for detecting the recording portion as the second sensor, it is possible to determine the size of the micro image and supply the recording paper of a size corresponding to it to the transfer device. , The number of sensors can be the same as the number of types of image size to be detected, and the configuration for signal processing can be simplified and the cost can be reduced.

Further, although the second sensor having the above-described configuration detects the micro image, the size of the micro image to be searched can be determined depending on whether the unrecorded portion between the micro images is detected. The excellent effect that the size of the micro image to be searched can be detected can be obtained even on the film on which the special mark shown is not printed.

[Brief description of drawings]

The drawings show an embodiment of the microfilm printer according to the present invention. FIG. 1 is a front view of the microfilm reader printer, FIG. 2 is a sectional view of the microfilm reader printer, and FIGS. 3 (a) and 3 (b) are A plan view of the microfilm, FIGS. 4A to 4C are front views showing a projected state of a micro image on a screen, and FIG. 5 is a perspective view showing a mounting portion of a blip mark recording paper size selection switch. 6A to 6D are plan views showing the positional relationship between the image size detection sensor and the microfilm, and FIGS. 7A to 7C are projection positions of the microfilm on the screen and paper feeding. FIG. 8 is an explanatory diagram showing the relationship with the set-up time of the control timer, FIG. 8 is a schematic configuration diagram of the control device of the microfilm reader printer, and FIGS. Is a flowchart showing the operation of the printer. (19) …… photoreceptor, (20) …… transfer device, (F) …… microfilm, (I) …… microimage, (IF)
…… Imaging device, (S ₁ ) …… Image size detection sensor,
(M) ...... frame search marks, (S _M) ...... first sensor, (B) a blank section of the ...... film, (S _B) ...... second
Sensor.

Front Page Continuation (56) References Japanese Patent Publication 47-40492 (JP, B1) Japanese Publication 57-7421 (JP, B2) Japanese Publication 52-37225 (JP, B2)

Claims (1)

[Claims] 1. A microfilm in which a plurality of microimages and search marks having a predetermined positional relationship with the microimage are aligned in the width direction of the film and are printed in the longitudinal direction of the film for searching the microimage,
An information retrieval device for retrieving a desired micro image, comprising a first sensor for detecting a retrieval mark, and a second sensor for detecting a micro image at a predetermined distance from the detection position of the first sensor in the longitudinal direction of the film. Control means for stopping the search target micro image at a predetermined position based on the detection result of the first sensor, and the second sensor detects the micro image when the search mark of the search target micro image is detected by the first sensor. Or an unrecorded portion between the micro images is detected, and a discriminating unit for discriminating the size of the micro image to be retrieved is provided.