JPH0713236A - Controller for spool stop position - Google Patents

Abstract

PURPOSE:To stop an index indicating the using state of a film housed in a film cartridge at a prescribed precise position. CONSTITUTION:Signal width generated by detecting a bar code by using a reflection type photosensor 30 is counted by a pulse generated from a photosensor 36 and an encoder plate 35 fitted to the rotary shaft of a motor 31 by synchronizing with the rotation thereof. By using the counted value, it is detected which position of the bar code is faced to the photosensor 30. Positional relation between the index and the bar code is previously decided. In order to stop the index at the precise position, the rotational speed of the motor 31 is lowered when the photosensor 30 is faced to some position. When the photosensor 30 is faced to the position of the bar code corresponding to the used, the in-use or the unuse state of the film, the rotation of the motor 31 is stopped at any position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spool stop position control device for a film cartridge, and more particularly to a spool stop position control device used for a film cartridge having a function of displaying the usage status of the film depending on the spool stop position. It is a thing.

[0002]

2. Description of the Related Art A film cartridge in which a film contained in a film cartridge can be easily identified as being unused, in use, used, or developed has been disclosed in US Pat. No. 5,049,912.
It is known from No. 5049913 and No. 5047794. In these film cartridges, the spool around which the film is wound is provided with an index plate for indicating the above-mentioned usage condition.When taking out the film cartridge from the camera, the film is completely wound in the cartridge and the spool is further wound. The display is stopped at a predetermined position corresponding to the usage status, and the usage status is externally displayed by the index plate.

On the other hand, the unique information (ISO sensitivity, the number of frames that can be photographed, etc.) peculiar to the film stored in the film cartridge is represented by a bar code, and this bar code is recorded on a bar code plate which rotates together with the spool, and the film cartridge. A camera for reading barcodes is known from US Pat. No. 5,625,011. According to this, after the film cartridge is loaded in the camera, the bar code plate is rotated by the spool rotation at the time of initial feeding of the film, and the bar code array pattern can be read by the photo sensor during that time. It is possible to automatically set data in various setting mechanisms on the camera side in correspondence with the read data.

[0004]

When the film cartridge is provided with both the function of displaying the usage status and the function of displaying the bar code as described above, for example, a camera using the film cartridge has a bar code reader and a bar code reader. A device for stopping the spool at an appropriate position according to the usage situation is required. However, if each of these devices is incorporated in a camera, an increase in cost due to an increase in mounting space and an increase in the number of parts cannot be avoided.

Further, in order to display the use status of the film on the index plate which rotates integrally with the spool, it is necessary to accurately control the stop position of the spool. However, the spool is originally rotated for feeding the film, and the rotation speed is not constant due to fluctuations in the feeding torque of the film. Therefore, it is difficult to stop the index plate at a predetermined position, and sometimes the index plate stops at an incorrect position.

The present invention has been made to solve the above problems, and a film cartridge for detecting the spool rotation angle with higher accuracy and stopping the index at an accurate position even if the spool rotation speed changes. It is an object of the present invention to provide an index stop position control device.

[0007]

In order to achieve the above object, the present invention comprises a bar code plate on which a bar code representing information unique to the film is recorded and a mark for displaying the usage status of the film. A motor for rotating a spool, which is used in a film cartridge which rotates integrally with a spool, and which determines a stop position of the spool so that the mark stops at a predetermined position corresponding to a usage condition of the film. A bar code reading means for reading a bar code array pattern from the bar code plate while the spool is rotating; an encode pulse generating means for generating an encode pulse each time the motor rotates a unit angle; and the bar code reading means. In response to the reading of a specific pattern in the barcode array by It has a counter for counting the down code pulses, and a stop control means based on the count value of said counter with film usage by controlling the stop position of the motor to stop the spool.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a perspective view showing a film cartridge having a bar code plate and an index indicating the usage state of the film. The cartridge body 10 has a spool 1
1 is rotatably attached. One end of the film 12 is fixed and wound around the spool 11. Further, the bar code plate 13 is provided on the spool 11.
Is fixed, and the bar code 14 is recorded in the circumferential direction. A window 15 for exposing the barcode 14 of the barcode plate 13 to the outside is formed in the upper portion of the cartridge body 10.

As shown in an example in FIG. 3, the bar code 14
Consists of black non-reflective bars and white highly reflective spaces. The bar code plate 13 is provided with a non-reflection surface, a black quiet zone 20 having an angle β, and a space 21, which is in contact with the black quiet zone 20 and has a high reflection surface having an angle θ in a clockwise direction. Note that β> 5θ.

Between the space 21 on the right of the black quiet zone 20 and the black quiet zone 20 in the clockwise direction, there is a data section for expressing the information peculiar to the film contained in the film cartridge. This data part is composed of a wide bar 22, a narrow bar 23, and a space 21 for separating the bar from the bar,
The bar always starts at a position adjacent to the space 21 to the right of the black quiet zone 20, the bars and the spaces 21 are alternately arranged, and finally the space 21 contacts the black quiet zone 20. The narrow bar 23 has an angle θ, and the wide bar 22 has an angle 2θ. Bar 22 represents a logic "1" and bar 23 represents a logic "0".

An index 11a in the shape of an arrow is integrally provided on the exposed portion of the spool 11 on the upper portion of the cartridge body 10. Characters that are unused, in use, or used are engraved on the upper portion of the cartridge body 10 at intervals of angle N.theta., And the index 11a indicates the state of the film stored in the film cartridge. You can judge whether it is in. Although not shown, when the cartridge body 10 is loaded in the camera, the barcode sensor 30 (see FIG. 1) faces the boundary position Q1 of the space 21 adjacent to the black quiet zone 20 in the counterclockwise direction. When this is done, the index 11a indicates that it is unused.
Position Q from position Q1 counterclockwise at angle N · θ
2 and the position Q3 from position Q2 to position Q3
When the photo sensor 30 faces this position, the indicators 11a indicate that the indicator 11a is in use or has been used.

FIG. 1 shows a circuit configuration of a main part of a camera to which the present invention is applied. FIG. 4 shows the configuration of the deceleration start position / stop position detection circuit (hereinafter, detection circuit) 40. Reflection type photo sensor 30 for bar code reading
Is a light emitting diode 30a and a phototransistor 30b.
And is arranged at a position facing the window 15 of the film cartridge in the camera. The photoelectric signal from the photo sensor 30 is sent to the detection circuit 40 and the barcode decoding unit 1.

The motor 31 is a microcomputer 32.
It is driven via the motor driver 33 by a command from the. The drive transmission mechanism 34 is switched to the winding operation during the normal film one-frame winding at the time of shooting, and the motor 31 is driven by the input of the exposure completion signal, and the driving force of the motor 31 is transmitted through the drive transmission mechanism 34. Although not shown, it is transmitted to the winding shaft provided on the camera,
The film 12 is wound around the winding shaft. When the film is rewound, the drive transmission mechanism 34 is switched for rewinding, and the driving force of the motor 31 is transmitted to the spool 11 via the drive transmission mechanism 34 to wind the film 12 into the cartridge body 10.

As shown in FIG. 5, an encoder plate 35 having a large number of slits arranged radially at a constant pitch is fixed to the rotary shaft of the motor 31. Then, a photo sensor 36 in which a light emitting diode 36a and a phototransistor 36b (see FIG. 1) face each other so as to sandwich the encode plate 35 is provided. The phototransistor 36b outputs a pulse each time the encoder plate 35 rotates and the slit passes between the encoder plate 35 and the light emitting diode 36a. Since the encoder plate 35 rotates integrally with the rotating shaft of the motor 31, the phototransistor 36b outputs a pulse synchronized with the rotation of the motor 31. This pulse causes transistor 37 to switch, resulting in transistor 37
From the above, an encode pulse is output every time the motor 31 rotates by a unit angle, and the encode pulse is input to the detection circuit 40.

In FIG. 4 showing the circuit configuration of the detection circuit 40, the encode pulse from the transistor 37 is input to the clock terminal of the counter 50. The counter 50 counts the number of encode pulses as a count value C. Further, the photoelectric signal from the photo sensor 30 that detects the barcode 14 is inverted by the inverter 41, and the differentiator 42
And to the inverter 43. Further, the signal inverted by the inverter 43 is input to the differentiator 44.

The differentiators 42 and 44 output one short pulse when the input signal rises. When the detection area of the photo sensor 30 moves from the space to the bar, the photoelectric signal from the photo sensor 30 falls from a certain signal level. At this time, the differentiator 42 outputs only one pulse because the signal inverted and rising by the inverter 41 is input. This pulse is output from the AND circuit 45,
46, 47, 48, 49 and the reset terminal of the counter 50. The counter 50 resets the count value C (C ← 0) when a pulse is input to the reset terminal.

The differentiator 44 generates only one pulse when the photo sensor 30 moves from the bar to the space, and this pulse is sent to the strobe terminal of the latch circuit 51. When a pulse is input to the strobe terminal, the latch circuit 51 takes in the count value C of the counter 50 at that time and holds it as a value Rf. That is, the latch circuit 5
The number 1 holds the number of pulses generated by the photo sensor 36 when the photo sensor 30 has detected the bar. This value Rf is determined by the digital comparators 52 and 5
Sent to 3.

The digital comparator 52 receives the value RB sent from the 3/2 multiplication constant multiplier 54 and the latch circuit 51.
By comparing with the value Rf of the above, it is determined whether the bar detected by the photo sensor 30 is the black quiet zone 20 or the bar of the data section. The value RB is the value R0 + R1 sent from the adder 61 multiplied by 3/2. Where R0 is the value of the latch circuit 59,
Corresponds to the number of encode pulses generated while facing the photo sensor 30. Similarly, R1 is the value of the latch circuit 60 and corresponds to the number of encode pulses generated while the photo sensor 30 was facing the wide bar 22 last time. Normally, the value R0 is a count value when the narrow bar 23 is detected by the photosensor 30 and the wide bar 22 is detected by the photosensor 30, and therefore, if the value Rf is the value RB or more, it can be determined as the black quiet zone 20. . The digital comparator 52 compares the value RB with the value Rf and sets the output to H level if RB <Rf, and otherwise outputs L level. This output is sent to the AND circuits 48 and 59 via the AND circuit 45 and the inverter 55.

The digital comparator 53 receives the value RR (= 1 / 2 (R
0 + R1)) and the value Rf of the latch circuit 51 are compared to determine whether or not the bar detected by the photosensor 30 is the narrow bar 23. Digital comparator 5
3 compares the value RR with the value Rf, and if RR <Rf, sets the output to the H level, and otherwise outputs the L level. This output is output through AND circuits 47 and 49, an inverter 57, an AND circuit 46, and an inverter 58.
Is sent to the AND circuit 48 via.

If the output of the digital comparator 52 is H level, the digital comparators 52 and 53 can judge that the value Rf is the count value when the black quiet zone 20 is detected, and the output of the digital comparator 52 is L level and the digital comparator 52. If the output of 53 is H level, the value Rf is judged to be the count value when the wide bar 22 is detected, and if the output of the digital comparator 53 is L level, when the narrow bar 23 is detected. It is judged to be the obtained count value.

The latch circuit 59 holds the count value obtained while the narrow bar 23 representing the logic "0" and the photo sensor 30 face each other as the value R0. When the output of the digital comparator 52 is at the L level and the output of the digital comparator 53 is at the L level, a pulse is output from the differentiator 42, the pulse is input to the AND circuit 48, and the AND circuit 48 latches the pulse. The value Rf of the latch circuit 51 is fetched by inputting it to the strobe terminal of 59 and held as the value R0. That is, the count value C obtained when the narrow bar 23 and the photo sensor 30 are facing each other is taken into the latch circuit 59 at the timing when the photo sensor 30 faces the next bar.

The latch circuit 60 is for holding the count value obtained while the wide bar 22 representing the logic "1" and the photo sensor 30 face each other as the value R1. When the output of the digital comparator 52 is at the L level and the output of the digital comparator 53 is at the H level, the differentiator 42 outputs a pulse to the AND circuit 49, and the AND circuit 49 inputs the pulse to the strobe terminal of the latch circuit 60. As a result, the value Rf of the latch circuit 51 is fetched and held as the value R1. That is, the count value obtained when the wide bar 22 and the photo sensor 30 face each other is fetched into the latch circuit 60 at the timing when the photo sensor 30 faces the next bar. The values of the latch circuits 59 and 60 are updated every time there is a pulse input to the strobe terminal. In this way, by updating the values of the latch circuits 59 and 60 with the number of encode pulses corresponding to the latest narrow bar 23 and wide bar 22, the feeding device such that the ratio of spool rotation to motor rotation changes. However, it is possible to correctly distinguish between wide and narrow.

The values of the latch circuits 59 and 60 are the adder 61.
Sent to. The adder 61 adds the values R0 and R1 and sends the result to the 3/2 times constant multiplier 54 and the 1/2 times constant multiplier 56. The 3/2 times constant multiplier 54 is an adder 61.
Value that is 3/2 times the value from (3/2 · (R0 + R1))
To the digital comparator 52. Further, the ½ multiplication constant multiplier 56 uses a value (½ · (R0 + R1)) obtained by multiplying the value from the adder 61 by ½, to the digital comparator 5.
Send to 3.

Each of the latch circuits 46 and 47 corresponds to the standard count value corresponding to the narrow bar 23 and the wide bar 22 of the apparatus immediately before the film is rewound. The counted value is set as the initial value.

The rotation angle integration counter 62 is a circuit that integrates which position the photosensor 30 is currently facing from the position P in FIG. 3 in the clockwise direction. When a pulse is generated in the differentiator 42 when the output of the digital comparator 52 is at the H level, the rotation angle integration counter 62 inputs a pulse from the AND circuit 45 to the reset terminal to set the integration count value RS to 0. That is, after detecting the black quiet zone 20, the photo sensor 30
Is reset when the bar faces the bar (when the photo sensor 26 faces the position P).

The output of the AND circuit 46 is connected to the + 2θ terminal of the rotation angle integration timer 62, and the AND circuit 4
The output of the digital comparator 53 is connected to the inverter 6 via the inverter 57, and the output of the differentiator 42 is also connected to 6. Further, the output of the AND circuit 47 is connected to the + 3θ terminal of the rotation angle integration timer 62, and the output of the digital comparator 53 and the differentiator 4 are connected to the AND circuit 47.
2 outputs are connected.

As a result, when the photosensor 30 detects a bar and it is determined that the count value at this time is due to the narrow bar 23, the angle 2θ until the photosensor 30 starts to meet the next bar. It is added to the integrated count value RS at the moment of doing. Similarly, for the wide bar 22, 3θ is added to the integrated count value RS.

The integrated count value R of the rotation integration counter 62
The S is sent to the digital comparators 63, 64, 65, 66. Since the integrated count value RS becomes an angular position in the clockwise direction from the position P of the bar code 14 facing the sensor 30, the value RS and each reference value are compared by the digital comparators 63, 64, 65, 66. Thus, the control signals for the deceleration position and the stop position are generated. The digital comparators 63, 64, 65 and 66 respectively include the integrated count value RS and the reference value 360-α-β-θ, 360-.
β-θ, 360- (N-1) · θ-β, 360- (2 ·
N-1) .theta. Is compared, and when the value RS exceeds this value, the output becomes H level.

The digital comparator 63 reduces the rotation speed of the motor 31 from when the photo sensor 30 faces the position of the angle 360-α-β-θ so that the photo sensor 30 faces any one of the positions Q1, Q2 and Q3. This is for generating a deceleration start signal for surely stopping when. In addition, the digital comparators 64, 65, 6
6 is the reference value 360-corresponding to the positions Q1, Q2, Q3.
β-θ, 360- (N-1) · θ-β, 360- (2 ·
N-1) .theta. To generate an unused stop signal, an in-use stop signal, and a used stop signal when the photo sensor 30 faces the positions Q1, Q2, and Q3. Each of these signals is sent to the microcomputer 31.

The microcomputer 32 uses the driver 3
The motor 31 is rotated through 3 to wind up or rewind. Furthermore, when a deceleration start signal is input from the detection circuit 40 during film rewinding, the driver 33 is instructed to reduce the rotation speed of the motor 30.
Further, the microcomputer 32 monitors the usage state of the film 12 with the number-of-photos-counter, and when the film is being rewound, a stop signal that coincides with the usage state of the film 12 is input after the deceleration start signal. Then, the motor 31 is instantaneously stopped via the driver 33.

The bar code decoding section 1 decodes the information of the bar code 15 from the photoelectric signal from the photo sensor 30 when the cartridge body 10 is loaded in the camera. When decoding, the width of the bar can be accurately detected by the encode pulse from the transistor 37.

The operation of the apparatus configured as described above will be described. FIG. 6 shows a timing chart of main signals. It is assumed that the cartridge main body 10 is loaded in the camera, the film 12 has already been fed, and several frames have been photographed, but there are still frames that can be photographed. When the film 12 is rewound, the drive transmission mechanism 34 is switched for rewinding and the motor 31 starts rotating.
The bar code plate 13 rotates counterclockwise in FIG. The microcomputer 32 is the cartridge body 1
When 0 is loaded, the bar code 14 is read, and the fact that the film 12 is in use is held as data from the preset number of shootable frames and the preset number of shot images.

The encode plate 35 rotates together with the rotary shaft of the motor 31, and accordingly, the encode pulse is input from the transistor 37 to the detection circuit 40. Then, this encode pulse is counted by the counter 50. Further, the photosensor 30 sends a photoelectric signal for detecting the bar and the space to the inverter 41 of the detection circuit 40.

Since the rotation angle of the motor 31 and the rotation angle of the spool 11 are proportional to each other, when the bar code plate 13 rotates by the angle θ, the rotation shaft of the motor 31 makes J rotations, and the photo sensor 36 makes the transistor 37. If K encoding pulses are generated for each rotation of the rotation axis of the motor 31, J.K encoding pulses are input to the clock terminal of the counter 50 every time the barcode plate 13 rotates by an angle θ. Has been done. The latch circuits 59 and 60 each have an initial value R0 =
J · K and R1 = 2 · J · K are set. The pulse input to the clock terminal of the counter 50 is generated with a sufficiently short cycle with respect to the change of the photoelectric signal output from the photo sensor 30 that detects the barcode 14.

From the middle of the bar code 14, the photo sensor 30
If the bar code 14 starts to be detected, the integrated count value RS is calculated by each digital comparator 63, 64, 6
Before reaching the reference value of 5,66, the photo sensor 30 faces from the space 21 to the black quiet zone 20, the space 21, and then to the next bar. At this moment, the falling photoelectric signal from the photo sensor 30 is input to the inverter 41. The differentiator 42 receives the rising signal from the inverter 41, generates one short pulse, and inputs it to the reset terminal of the counter 50. The counter 50 is reset by this pulse and the count value C becomes zero.

The counter 50 counts the encode pulse from the transistor 37 immediately after reset. When the photo sensor 30 faces the next space 21,
The rising photoelectric signal from the photo sensor 30 is input to the differentiator 44 via the inverters 41 and 43. Differentiator 4
From 4, a short pulse is generated, and this pulse is input to the strobe terminal of the latch circuit 51. Latch circuit 51
Takes the count value C of the counter 50 at this moment, holds it as Rf (Rf ← C), and sends the value Rf to the digital comparators 52 and 53.

The initial values R0 and R1 set in the latch circuits 59 and 60 are sent to the adder 61, and the value (R0 + R1) is transferred to the 3/2 times multiplier 54 and the 1/2 times multiplier 56. To the value RB (=
3/2 · (R0 + R1)) is the digital comparator 52
Sent to. Further, the value RR is output from the 1/2 multiplier 56.
(= 1/2 · (R0 + R1)) is sent to the digital comparator 53.

The digital comparator 52 compares the value Rf with the value RB. The count value Rf when the black quiet zone 20 is detected is β> 5θ, so 5 ·
Since it becomes J.K or more and the value RB = 9/2 (J.K), the output becomes H level. Further, the digital comparator 53 compares the value Rf with the value RR. Value RR = 3/2
Since it is (J / K), the output becomes L level.

Further, at the moment when the photo sensor 30 faces the next bar 22 or bar 23 from the space 21 as the rotation of the bar code plate 13 progresses, a pulse is again generated from the differentiator 44. With this pulse, the counter 50 sets the count value C to 0 and starts counting again. Further, since the output of the digital comparator 52 is at the H level, the AND circuit 45 outputs the pulse from the differentiator 42 to the reset terminal of the rotation angle integration counter 62. The rotation angle integration counter 62 sets the integration count value RS to 0.
To The other AND circuits 46, 47, 48, 49 are L
No pulse is output because the level is input.

When the photosensor 30 faces the space 21 from the bar 22 or 23, the current timer value C is held in the latch circuit 51 as the value RS in the same manner as described above. The value Rf is sent to the digital comparators 52 and 53 and compared with the values RB and RR. Here, if the detected bar is wide, Rf = 2 · J · K, so the output of the digital comparator 52 becomes L level and the output of the digital comparator 53 becomes H level. Here, at the moment when the photo sensor 30 faces the next bar, the AND circuit 47 outputs a pulse by the pulse from the differentiator 42. A pulse is input to the + 3θ terminal of the rotation angle integration counter 62, and the integrated count value RS is incremented by 3θ.

Further, all the inputs of the AND circuit 49 are also H level.
It goes to a level and outputs a pulse to the strobe terminal of the latch circuit 60. The latch circuit 60 takes in the count value Rf of the latch circuit 51 at this moment and holds it as R1, and the value R1 is sent to the adder 61. At this point, the output value from the adder is changed.

If the detected bar is narrow, the output of the digital comparator 52 becomes L level and the output of the digital comparator 53 becomes L level because Rf = J · K. . At the moment when the photosensor 30 faces the next non-reflection surface, in this case, the differentiator 42
The AND circuit 46 outputs a pulse by the pulse from. A pulse is input to the + 2θ terminal of the rotation angle integration counter 62, and the integrated count value RS is incremented by 2θ.

Further, all the inputs of the AND circuit 48 are H level.
It goes to a level and outputs a pulse to the strobe terminal of the latch circuit 59. The latch circuit 59 takes in the count value Rf of the latch circuit 51 at this moment and holds it as R0, and the value R0 is sent to the adder 61. At this point, the output value from the adder is changed.

In the same manner as above, the bar 22 or the bar 23
Is detected and compared by the digital comparators 52 and 53 one after another. In the case of the wide bar 22, the integrated count value RS is incremented by 3θ, and in the case of the narrow bar 23,
The integrated count value RS is incremented by 2θ.

The integrated count value RS of the rotation angle integration counter 62 is the digital comparator 663, 64, 65, 6
6 is compared with each reference value as needed. Then, when the integrated count value RS ≧ 360−α−β−θ, the deceleration start signal is input to the microcomputer 32 to surely stop at a predetermined position. When the deceleration start signal is input, the microcomputer 32 decelerates the rotation speed of the motor 31 via the motor driver 33 at this moment, regardless of the usage state of the film 12. The motor 31 will rotate at a rotation speed that can be instantaneously stopped.

The microcomputer 32 is the film 1
Since the use state of No. 2 is in use, in order to stop the index 11a at the position indicating the character in use, the input of the in-use stop signal is waited for.

Further, the integrated count value RS is incremented so that the integrated count value RS ≧ 360− (2 · N−
When 1) -β, the used stop signal is output from the digital comparator 66 to the microcomputer 32. Since the used condition of the film 12 is not used,
The microcomputer 32 ignores this signal and waits for a busy signal to be input.

When the motor 31 continues to rotate, when the integrated count value RS ≧ 360− (N−1) −β is reached, it is input from the digital comparator 65 to the busy stop signal microcomputer 32. The microcomputer 32 stops the motor 31 at this moment. The photo sensor 30 stops at the position facing the position Q2, and the index 11a
Refers to the character in use.

After this, the cartridge main body 10 from the camera
Take out. The index 11a indicates the used character on the upper portion of the taken out cartridge body 10, and the film 12 contained in the cartridge body 10 is in use, and it is displayed that there are still photographable frames. There is.

Here, when the film 12 has been used, the microcomputer 12 determines the film 12 from the preset number of photographable frames and the number-of-photographing counter set in advance.
Is used, the used data is held, the integrated count value RS is incremented, and when the integrated count value RS ≧ 360− (2 · N−1) −β, the digital comparator At the moment when the used stop signal is input to the microcomputer 32 from 66, the motor 3
Stop 1 The photo sensor 30 stops at a position facing the position Q2, and the index 11a indicates a used character. The film 12 stored in the cartridge body 10 taken out from the camera is displayed as being used.

When the film cartridge is loaded into the camera and then taken out without taking a picture even once, an unused display is given by the index 11a. In this case, the used stop signal and the in-use stop signal are ignored and the integrated count value R
When S ≧ 360−β−θ, an unused stop signal is sent from the digital comparator 64 to the microcomputer 3
The motor 31 is stopped at the moment when it is input to 2. The photo sensor 30 stops at the position facing the position Q1 and the index 11
a indicates an unused character. The film 12 contained in the cartridge body 10 taken out from the camera
Is displayed as unused.

In the above embodiment, the bar width of the bar code is sequentially discriminated and the rotation angle obtained from the width is integrated to calculate the deceleration position and the stop position. However, the encode pulse synchronized with the rotation of the motor is used. If the rotation angle of one spool is known, the rotation angle of the spool can be recognized directly by this encoder pulse. This example will be described below.

FIG. 7 is a diagram showing the structure of the main part.
The output of the photo sensor 36 is input to the microcomputer 70 as an encoder pulse. In addition, the photoelectric signal output from the photo sensor 30 is also output to the microcomputer 70.
Entered in. The microcomputer 70 has a built-in RAM for storing variables necessary for processing and a ROM in which a program necessary for processing is written. The same parts as those in the above embodiment are designated by the same reference numerals.

The basic procedure of the processing of the microcomputer 70 is shown in the flow chart of FIG. This process will be briefly described. When the motor 31 rotates and the bar code plate 13 starts rotating, the microcomputer 70
Monitors the photoelectric signal output from the photo sensor 30 and waits for the photo sensor 36 to face the starting end of the space 21. The microcomputer 70 includes the photo sensor 30.
When the leading edge of the space 21 is detected and the beginning of the space 21 is detected, the photoelectric signal from the photosensor 30 is further monitored, and this time the trailing edge of the photoelectric signal due to either of the black quiet zone 20 and the bars 22 and 23 is detected. At the time of detection, the variables M1 and M2 are set to 0.

The microcomputer 70 increments the variables M1 and M2 by one and counts each time one pulse is input from the photosensor 36. In addition,
The count of the variables M1 and M2 may be incremented by causing the microcomputer 70 to generate an interrupt process each time an encoder pulse is input to the microcomputer 70. Next, the variables M1 and M2 obtained when the space 21 is detected are compared with a value CONST (for example, 9/2 (J · K)) to determine whether the black quiet zone 20 is detected. Where M1 <CO
If it is NST, it is determined that the detected bar is not in the black quiet zone 20, and when the detection of the bar is subsequently started, the variables M1 and M2 are set to 0, and the photo sensor 3
Count the number of encoder pulses from 6. M1 ≧
The above operation is continued until it becomes CONST.

If M1 <CONST, it is judged that the detected bar is in the black quiet zone 20, and the variable M1 is set to 0 by the change in the signal when the photo sensor 30 faces the next bar 22 or 23. , Start counting. At the same time, the value of the variable M2 is written in the RAM as Msave, but the variable M2 is continuously incremented from the value at that time. At the time when the next space 21 is detected, the variable M1 is set to the value CONST in order to determine whether or not the barcode 14 has rotated once.
Compare with. If M1 <CONST, the variable M1 is set to 0, the procedure of writing the value of the variable M2 to the RAM as Msave is returned, and this operation is repeated until M1 ≧ CONST.

If M1 ≧ CONST, it means that the black quiet zone 20 is detected again, and the value Msave at this time is the number of encode pulses output by the photosensor 36 when the bar code plate 13 makes one rotation. . That is, ω = 360 / Msave is the rotation angle of the barcode plate 13 corresponding to one encode pulse. Here, the variable M1 is set to 0 and the counting is restarted. The microcomputer 70 compares the value M1 · ω with a reference value indicating an angle such as a deceleration position, and controls deceleration and stop of the motor 31. Even in this case, the index 11a can be accurately stopped at the desired position.

In the above-described embodiment, the rotation angle of the bar code plate per one encode pulse is detected by detecting that the bar code plate has rotated once, and is calculated from the number of encode pulses counted during that time. Since the rotation angle of the bar code plate per one encode pulse can be known from the gear ratio between the spools and the number of slits in the encoder plate at the design stage, a preset value may be used.

In the above two embodiments, the encoder composed of the photo sensor and the blade member was used to detect the rotation angle of the motor, but the ripple component contained in the drive current flowing between the motor and the motor driver and the motor. A signal proportional to the rotation angle of the motor, such as a signal having strength and weakness output from the reflective photo sensor, may be used by detecting the tooth row of the drive gear with the reflective photo sensor.

[0060]

As described above in detail, according to the present invention, the relative angle of the bar code can be determined from the rotation angle of the motor, which is proportional to the rotation angle of the bar code plate, and the bar code detection result. Since the motor is controlled and stopped by judging the rotation angle, the bar code and the index of which the positional relationship is fixed are stopped at a predetermined position to definitely indicate the usage state of the film accommodated in the film cartridge. be able to.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a main part of an index stop position control device.

FIG. 2 is an external view of a film cartridge used in the present invention.

FIG. 3 is an explanatory diagram showing an example of a barcode.

FIG. 4 is a circuit diagram of a deceleration start and stop position detection circuit.

FIG. 5 is an explanatory diagram of a photo sensor and an encoder plate attached to a motor.

FIG. 6 is a timing chart of main signals.

FIG. 7 is a circuit diagram of another embodiment.

FIG. 8 is a flowchart showing a processing procedure of another embodiment.

[Explanation of symbols]

 10 film cartridge body 11a index 13 bar code plate 14 bar code 31 motor 30 photo sensor 35 encoder plate 36 photo sensor 40 deceleration start position and stop position control circuit 62 rotation angle integration counter

Claims (1)

[Claims] 1. A bar code plate on which a bar code representing information unique to the film is recorded, and a mark for displaying the use status of the film are used for a film cartridge that rotates integrally with a spool, and the mark is used. In a spool stop position control device for determining a stop position of a spool so as to stop at a predetermined position corresponding to a usage state of a film, a motor for rotating the spool, and a bar code from the bar code plate during rotation of the spool. Bar code reading means for reading an array pattern, encode pulse generating means for generating an encode pulse each time the motor rotates by a unit angle, and the specific pattern in the bar code array read by the bar code reading means. A counter that counts the encode pulses in response to
A spool stop position control device, comprising: stop control means for controlling a stop position of the motor based on a film use condition and a count value of the counter to stop the spool.