JPH05313245A - Camera and film information detection circuit - Google Patents

Abstract

PURPOSE:To attain the high speed of a film information processing by installing a film information detection circuit and also installing a couter circuit outside a control circuit. CONSTITUTION:A film cartridge rewound halfway when a rewinding switch 20 is turned on is loaded in a camera and a back cover is closed, when a back cover switch 19 is turned on, the winding of a film F is started. On the way of winding the film, the film information recorded on the magnetic track T of the film F as the train of data character started with an ID sentinel is read out by a magnetic head H, and also, the number of ID sentinels in the film information detected by an ID detection circuit 21 is inputted and counted at every frame. And by adding an ID count circuit 49 outside the control circuit 27, it becomes unnecessary for the control circuit 27 to detect the ID sentinel. Thus, the processing by the control circuit 27 is simplified, so that the whole processing time can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to drive a magnetic head during the feeding by the film feeding means after the end of photographing so that the camera is recorded on the film information previously written in the magnetic memory portion of the photographed frame. The present invention relates to an improvement in a camera and a film information detection circuit which use a film with a magnetic storage unit having a writing instruction means for performing overwriting of information.

[0002]

2. Description of the Related Art US Pat. No. 4,878,075 discloses a camera which uses a film cartridge that also stores the leading end of a film and enables the film to be rewound halfway (taken out halfway) and the film cartridge can be reloaded. ing.

According to the above proposal, the film is provided with a magnetic storage section made of a transparent magnetic layer, and the camera writes information in the magnetic storage section or reads information previously recorded therein. Have a magnetic head,
There is disclosed a technique for discriminating between exposed and unexposed when a film cartridge that has been rewound midway is reloaded.

Further, a technique for improving the above is disclosed in Japanese Patent Application No. 2-29.
No. 7828.

16 to 22 show a conventional example of a camera in the same technical field as the present invention.

FIG. 16 is a perspective view showing the main structure of the camera. In FIG. 16, 1 is a taking lens, 2 is a lens actuator for driving the taking lens 1 and a lens encoder for generating a lens position signal, and 3 is a lens. Shutter,
Reference numeral 4 is a photometric sensor for AE, 5 is a lens that determines the light receiving angle of the photometric sensor 4, 6 is a block including a distance measuring sensor and a finder, and 7 is a perforation P of the film F.
Photoreflector which detects ₁ and P ₂ and generates a signal for indexing one frame of the film F, 8 is a film feeding motor arranged in a spool, 9 is deceleration and switching between winding and rewinding The gear train 10 for performing the above is a rewinding fork.

C is a film cartridge that stores the film with the front end of the film exposed, F is the above-mentioned film having a magnetic storage unit (magnetic track T) on the base side, and P ₁ and P ₂ are images. The above-mentioned perforation corresponding to the screen A, H is a magnetic head for writing information to or reading information from the magnetic track T on the film F. Reference numeral 11 denotes a pad for pressing the film F against the magnetic head H, which has a concave portion at the central portion for enhancing the adhesion between the film F and the head gap. 12 is a pad advancing / retreating control mechanism that presses the pad 11 against the magnetic head H with a predetermined pressure with the film F sandwiched only during film feeding, 16 is a release button, 17 is a switch (SW1) for starting photometry and ranging. , 18 are switches (SW) for starting the sequence of opening the shutter and feeding the film.
2) and 20 are rewind switches that perform midway rewinding.

FIG. 17 is a circuit block diagram of a conventional camera, and the same parts as those in FIG. 16 are designated by the same reference numerals.

In FIG. 17, 19 is a back cover switch for detecting the closing of the back cover, 21 is an ID detection circuit for detecting an ID sentinel in the film information, 22 is a head amplifier for the magnetic head H, 23 is a buffer, 24 is a decoder, 2
Reference numeral 5 is an encoder, 26 is a buffer, 27 is a control circuit configured by a microcomputer for performing sequence control of each circuit, and 28 is a motor driver for driving the film feeding motor 8.

Now, the operation of the control circuit 27 will be described with reference to the flowchart of FIG. In the camera of this embodiment, the film F is once wound up,
A so-called prewind method in which the film is rewound for each frame is assumed.

First, the operation when a film cartridge which is not used at all is loaded in the camera will be described.

When the film cartridge C is loaded into the camera, the back cover is closed, and the back cover switch 19 is turned on,
Proceeding from step 101 to step 102, the film feeding motor 8 is driven through the motor driver 28 to start the winding of all the films F. And step 10
3, during film winding, film information such as film sensitivity, specified number of frames, film type, etc. recorded on the magnetic track T of the film F as a string of data characters starting from the ID sentinel (information head signal) is recorded on the magnetic head. Read by H.

The read film information is amplified by the head amplifier 22 and A / D converted, and then the buffer 2
3 and then decoded by the decoder 24 and transferred to the control circuit 27.

In step 103, the ID
The detection circuit 21 continues to detect the N-bit ID sentinel (for example, “10000000”) of the film information, and the control circuit 27 inputs and counts this detection output. In the next step 104, the number of ID sentinels of the film information is compared with a predetermined number which is a threshold value of whether or not the frame is "exposed", and when it is determined that the frame is "exposed" (ID If the number of sentinals is less than or equal to a predetermined number, the process proceeds to step 105 (this step is an important part when the film rewound midway is reloaded, details will be described later) (Number of ID sentinels> predetermined number) proceeds to step 107.

Since it is assumed here that the unused film cartridge C is loaded as described above, the process proceeds from step 104 to step 107. In this step 107, the number of fed frames is counted from the output of the photo reflector 7 and it is judged whether or not the number of specified frames read previously is reached. If it is judged that the number has been reached, the process proceeds to step 108, The driving of the film feeding motor 8 is prohibited and the film winding is stopped.

In step 109, the switch SW
It is determined whether or not 1 is ON, and when it is determined to be ON, the process proceeds to step 110, and each operation of photometry and distance measurement is performed. In the next step 111, the shutter speed, aperture value, etc. obtained by the photometry and distance measurement operations are converted into camera information and transferred to the encoder 25.

The encoder 25 encodes the transferred camera information, and the buffer 26 stores the coded information.

In the next step 112, it is determined whether or not the switch SW2 is turned on. If it is determined that the switch SW2 is turned on, the process proceeds to step 113 to perform a known exposure operation.

That is, the control circuit 27 inputs the lens position signal from the lens encoder 2b via the lens actuator 2a, and the photographing lens 1 comes to a position corresponding to the distance measurement information obtained in step 110, whereby the lens actuator 2a To stop the driving of the taking lens 1, that is, the focus operation. At the same time, the shutter 3 is opened and closed for a time determined by the output of the photometric sensor 4.

At step 114, rewinding of the photographed frame (one frame rewinding) is started. And step 115
In the process of rewinding the film, head amplifier 2
The camera information stored in the buffer 26 via the 2 is sent to the magnetic track T of the film F on the magnetic track T of the film F, and an N-bit ID sentinel different from the ID sentinel of the film information (for example, “00000000”).
Write in the form of a sequence of data characters beginning with. In step 116, it is judged from the output of the photo reflector 7 whether or not the rewinding of the photographing frame is completed. If it is judged that the rewinding of the photographing frame is completed, the process proceeds to step 117, in which the film F is not exposed. It is determined whether or not there is a piece (whether or not there is a remaining piece), and if there is, a step 118
Go to. In step 118, it is judged from the state of the rewind switch 20 whether or not the midway rewind is instructed, and if the midway rewind is not instructed,
The process returns to step 109 to prepare for the next shooting.

In step 117, the film F
If it is determined that there is no remaining frame in the frame, or if rewinding is performed midway in step 118, the process proceeds to step 119 and the continuous output from the photoreflector 7 is stopped, that is, the leading edge of the film passes the position of the photoreflector 7. The rewinding of the film F is continued until. As a result, only the leading edge of the film is not wound into the film cartridge C. If the film cartridge at this time is of a type in which the tip of the film can be pushed out of the cartridge by the rotation of the fork 10, the film rewinding is continued until the tip of the film is also housed in the cartridge. You may.

With the above, a series of operations when the unused film cartridge C is loaded is completed.

Although not described above, the pad 11 is a pad advance / retreat control mechanism 12 only while the film F is moving.
Is pressed by the magnetic head H to read out magnetic information,
Writing is becoming more reliable.

Next, the operation when the film cartridge that has been rewound (taken out halfway) (the film cartridge that contains the film used halfway) is loaded again into the camera in step 118 will be described.

When the rewind switch 20 is turned on, the film cartridge that has been rewound midway is loaded into the camera, the back lid is closed, and when the back lid switch 19 is turned on, the same as when an unused film cartridge C is loaded. The operation proceeds from step 101 to step 102 to start winding the film F. Similarly in step 103, during the film winding, the film sensitivity recorded as a string of data characters starting from the ID sentinel on the magnetic track T of the film F,
The magnetic head H reads the film information such as the specified number of frames and the type of film, and the number of ID sentinels of the film information detected by the ID detection circuit 21 is input and counted for each frame. In the next step 104, the number of ID sentinels in the film information is compared with a predetermined number which is a threshold value of whether or not the frame is "exposed", and "ID sentinel number≤predetermined number" is obtained. When the frame is detected, it is determined that the frame is "exposed" (a method of this determination will be described later), the process proceeds to step 105, the drive of the film feeding motor 8 is prohibited, and the film winding is immediately stopped. In the next step 106,
The film feeding motor 8 is driven in the reverse direction to rewind one frame. As a result, the unexposed frame is located at the aperture position of the camera.

Here, the determination in step 104 will be described in detail. The control circuit 27 counts the number of ID sentinels of film information recorded in advance on each frame. At this time, if a certain frame is an “unexposed” frame, all the ID sentinels in one frame will be detected by the magnetic head H (for example, if there are 15 ID sentinels in one frame, 15 will be detected). However, in the case of the “exposed” frame, at least one portion has been rewritten to the camera information, so that the number of detectable film information ID sentinels decreases (for example, 9 pieces). Therefore, when the number of counted ID sentinels is larger than the predetermined number (for example, 9), the control circuit 27 determines that the frame is "unexposed" and determines from step 104 to step 10.
7. If the number is less than a predetermined number such as 9 as in the above example, the frame is judged to be "exposed" and the process proceeds from step 104 to step 105 to detect film winding and perforation (not explained above). However, inputting to index the pieces) is immediately stopped, and in the next step 106, one piece is rewound to locate the head,
Enters the shooting standby state.

Next, details of the film information and the camera information will be described with reference to FIGS. 19 to 21.

FIG. 19 is a view showing the arrangement of the film information track TM and the camera information track TC on the film F and the structure of the film information block BM in the film information track as viewed from the base surface.

The film information track TM and the camera information track TC are arranged along the film F, and the camera information track TC is formed in the film information track TM.

The camera information track TC is located at the head gap position of the magnetic head H of the camera, and the head gap is always in the film information track TM even when the film is slightly moved up and down during recording and reproduction.

The film information track TM is composed of a series of film information blocks BM as shown in FIG.
The sentinel portion is shown by vertical lines. In this example,
As described above, the ID sentinels of 15 pieces of film information are included in one pitch (one frame) of the perforations P ₁ and P ₂ .

In this embodiment, the prewind structure is adopted, and the direction of film information and the direction of camera information are opposite to each other, as will be described later. Therefore, I of the film information
It goes without saying that the D sentinel needs to have a bit order different from all the film information characters and the bit string formed by their arrangement, the ID sentinel of the camera information when reversely reproduced, the data character, and the bit string created by them. Let's do it.

20 and 21 are views showing the length of the camera information TC on the film F, as viewed from the base surface as in FIG.

In FIG. 20, L is a boundary between photographing frames (frames already photographed), which is a reference position of the head gap of the magnetic head H. HO is the degree of freedom on both sides of the head position (head offset), and MT is the variation in frame feed positioning. Therefore, the maximum length C of the camera information TC that can be written is C.
_MAX is given by C _MAX = L- (HO + 2MT) = 1 frame total length- (head freedom + frame feed tolerance). The structure of each camera information block BC therein is such that it starts with an N-bit ID sentinel different from the film information TM in the opposite direction, is followed by a data character, and is filled with a binary "0" after the end of the data. Maximum length C _{MAX of} camera information TC that can be written
Is the area where all cameras must not write outside this area. By this regulation, overlapping of written information is prevented in the filled cameras in the head offset HO. The maximum writable length C _MAX is preferably symmetrical with respect to the screen center CLA.

In FIG. 20, C _MIN is the minimum length in which the camera information block BC can be written, and may be the minimum required as shown in the figure, or from other conditions, the length is set to “0” as shown in FIG. May be adjusted. The minimum writable length C _MIN of the camera information block BC is an area that the camera must write. Further, it is desirable that the minimum writable length C _MIN is also symmetrical with respect to the image center CLA.

Next, a method of discriminating between exposed and unexposed frames by detecting the ID sentinel of the film information TM will be described with reference to FIG.

In FIG. 22, LS is a scan area in one frame of the magnetic head H, and if the difference in head position by the camera is less than or equal to the offset HO, there is no overlap of write information, so the same as the total length of one frame. You can see.

22A is an unexposed frame, O ₁ is the output of the ID detection circuit 21 in this case, and FIG. 22B is the camera information TC written over the maximum writable length C _MAX. exposure with Sumikoma, O ₂ is the output of the ID detection circuit 21 in this case, FIG. 22 (C) is exposed with a camera information TC was written over a minimum length C _MIN to put writing Sumikoma, O ₃ is the output of the ID detection circuit 21 in this case.

It can be seen from the output O ₃ of the ID detection circuit 21 that the maximum number of ID sentinels (hereinafter referred to as the number of IDs) in the "exposed" frame is nine. Therefore, the number of IDs 0 to 9 can be identified as "exposed" pieces and the number of IDs 10 to 15 "unexposed" pieces. When a reproduction error occurs, the detection of the number of IDs is reduced, but in the "unexposed" frame, 15 I's are detected.
Correct detection can be made if ten D sentinels can be detected. This means that even if the reproduction error rate is low, the probability of making a correct determination is much higher than in the past. Also, for "exposed" pieces, this reduction is not a problem at all.

[0040]

The above-mentioned conventional example (Japanese Patent Application No. 2-297828) does not disclose a specific structure for detecting film information or the like in the circuit block. Further, in another conventional example, since the counting circuit for counting the number of film information and the like is not provided, there is a drawback that the control circuit cannot process at high speed.

The present invention has been made to solve the above-mentioned problems, and comprises a circuit for detecting film information,
Also, a camera that can count the number of film information,
An object is to provide a film information detection circuit and an improved film information detection circuit.

[0042]

In order to achieve the above-mentioned object, the present invention provides a circuit for detecting film information according to claim 1 by a shift register circuit and a comparison circuit. In Item 2, a film in which a larger number of pieces of film information than the number of pieces of camera information written by the magnetic head after the shooting is preliminarily written in the magnetic storage portion of each frame is used, and in the exposure state determination means, A circuit is provided for counting the number of pieces of film information that have been written in the magnetic memory section of the frame indexed by the frame indexing means when the film cartridge containing the used film halfway is reloaded. According to claim 3, the other film information after detecting the film information is held in the shift register circuit or the number of film information is shifted. Held in register circuit constituting a camera provided with a circuit for outputting the respective information from the shift register circuit to an external circuit. And as the film information detection circuit, a circuit for detecting the film information,
The shift register circuit has a bit length shorter than the bit length of the film information, a comparison circuit, a storage circuit, and a counter circuit.

[0043]

According to the present invention, the film information detecting circuit is provided, and further the counting circuit is provided outside the control circuit, whereby the processing speed of the control circuit is increased. further,
By providing a circuit that sequentially changes the comparison value of the comparison circuit, the bit length of the shift register circuit is shorter than the bit length of the ID sentinel.

[0044]

1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a time chart for explaining FIG. In FIGS. 1 and 2, 128, 29 and 30 are input terminals and 3
Reference numeral 1 is a knot circuit, 32 and 33 are shift registers (for example, SN74199 manufactured by TI), 34 and 35 are 8-bit comparators (for example, can be configured by cascade-connecting two SN7485s manufactured by TI), and 36 is a NAND circuit. , 37 are output terminals.

Here, in the configuration of FIG. 1, the signal waveforms shown in FIG. 2 are input to the input terminals 128, 29 and 30.

The DCDDATA signal is input to the input terminal 128. This DCDDATA signal is a signal obtained by converting a magnetic signal into a binary signal.

The -DNDPPM signal is input to the input terminal 29. The -DNDPPM signal is a signal that falls for one system clock for each 1-bit data obtained by converting a magnetic signal into a binary signal.

The CLK signal (system clock signal) is input to the input terminal 30.

In FIG. 2, one bit of DCDDATA is present while the -DNDPPM signal falls. Therefore, in the figure, "0" and "1" are indicated by numbers between the -DNDPPM signal and the DCDDATA signal.

Here, the 8-bit comparator 34 of FIG.
And 35 are input signals A7, A6, A5, A4, A3, A
When 2, A1 and A0 are binary signals of 11111110B and FEH of hexadecimal number, the output signal AEQB (A
Equal to B) becomes 1. Further, the NAND circuit 36 causes the output terminal -DS only when the output signals AEQB of the 8-bit comparators 34 and 35 become 1 at the same time.
COMP becomes 0. This state indicates that the ID sentinel has been detected.

FIG. 3 is a block diagram showing another embodiment of the present invention. 38, 39 and 40 are input terminals, 41 and 43 are 4-bit counters (for example, SN74163 manufactured by TI), 4
2 is a knot circuit, and 44, 45, 46, 47 and 48 are output terminals.

Here, the input terminal 38 is connected to the DNDP of FIG.
The PM signal is added, and the input terminal 39 receives -DS of FIG.
The COMP signal is applied, and the system clock signal is applied to the input terminal 40.

According to this configuration, the -DSCOMP signal is 0
Then, the 4-bit counter 41 counts up by 1. Therefore, by adding the ID count circuit 49 shown in FIG. 4, the control circuit 27 does not have to perform the ID sentinel detection as compared with the conventional example of FIG. 13 as shown in FIG.

FIGS. 6 and 7 are circuit block diagrams showing a second embodiment of the present invention, and FIGS. 8A and 8B are time charts for explaining FIGS. 6 and 7.

In this embodiment, the data after the ID sentinel is stored in the shift register by 3 bytes, and the 3 bytes of data are stored in the signal SRDRD from the control circuit 27.
Signal to the control circuit 27 by the signal SRCLK
Output as TA signal.

Also, the number of ID sentinels is counted, and the result is signal SRDRD signal and SR from the control circuit 27.
It is output as an SRDATA signal to the control circuit 27 according to the CLK signal.

6 and 7 show the ID detection data buffer circuit 50 shown in FIG.

Each drawing will be described below.

In FIG. 6, a shift register 57 is added to FIG. 1, and a signal for controlling the shift register is added for communication with the control circuit 27. Further, after detecting the ID sentinel, the counters 59, 60 for counting 3 bytes (24)
Is added.

In FIG. 7, in addition to the ID sentinel number counting circuit of FIG. 3, inputs of communication signals SRDRD signal and SRCLK signal from the control circuit 27 are provided.

In FIGS. 6 and 7, 51, 52, 53,
54, 58, 64, 75, 80, 83 and 84 are AND circuits, 55, 56, 61, 62, 63, 85 and 87 are OR circuits, 57 is a shift register, 59 and 60 are 4-bit counters and 65 and 68. , 69, 70 are input terminals, 66, 6
7, 88 are output terminals, 71, 74, 76, 79, 81,
82 is a knot circuit, and 72, 73, 77, 78, 86 are D
It is a flip-flop.

FIGS. 8A and 8B are time charts showing the operation of the circuits of FIGS. 6 and 7.

FIG. 8A shows 3 after the ID sentinel is detected.
This shows the reading of byte data. Now, the 65AL / -FRM signal at the input terminal is 1.

As described in FIG. 1, when the -DSCOMP signal becomes 0 and the ID sentinel is detected, the 4-bit counters 59 and 60 load E8H in hexadecimal. Then, each time the -DNDPPM signal becomes 0, it counts up by one, and when it becomes FFH, the count-up is stopped. Then, 3BCNT of the output terminal 67 becomes 1.

The D flip-flop 86 shown in FIG. 7 is 3BCN.
When T becomes 1, 1 is continuously output to 3BSET of the output terminal 88. When the SRDRD signal becomes 1 from the control circuit 27, 3BSET of the output terminal 88 becomes 0.

When the SRDRD signal becomes 1, the D flip-flops 72 and 73 will be described in FIG.
The SRDRD signal becomes 0. When the SRDRD signal becomes 1, the data Q27 after the ID sentinel is detected is output to the output terminal 66SRDATA signal.

Next, when the SRCLK signal from the control circuit 27 changes from 0 to 1, the D flip-flop 77, shown in FIG.
78 causes -UPSRCLK to become 0, and the shift registers 32, 33 and 57 shift by one data. Therefore, Q26 is output as the SRDATA signal from the output terminal 66.
Also, even if the SRCLK signal changes from 1 to 0, SRDA
The TA signal does not change.

Similarly, when the SRCLK signal is raised, a signal for 3 bytes can be read into the control circuit 27. Now, set the AL / -FRM signal of the input terminal 65 to 0.
And

FIG. 7 shows the reading of the number of ID sentinels. The control circuit 27, during film feeding,
The perforations P ₁ and P ₂ are detected, and the input terminal 68SRDRD signal is set to 1 for each frame on the film F. Then, the outputs of the 4-bit counters 41 and 43 forming the ID sentinel counter shown in FIG. 3 are loaded into the 8-bit shift register 57.

At this time, the most significant bit ID4 of the ID sentinel counter (here, a 5-bit counter) is output.

Next, the SRCLK signal from the input terminal 70 is set to 1
Then, the shift register shifts 1 bit, so
The next ID3 is output. Similarly, up to ID0 is output.

FIGS. 10 and 11 are diagrams showing a third embodiment of the present invention and correspond to the ID detection data buffer circuit shown at 23 in FIG.

In FIGS. 10 and 11, 38 is an input terminal,
39 is a NAND circuit, 40, 53 and 59 are 4-bit counter circuits (for example, SN74163 manufactured by TI), 41 and 4
3, 44, 45, 46, 51 are knot circuits, 42, 4
7, 48, 49, 52 are AND circuits, 50 is an OR circuit,
Reference numeral 51 is a D latch circuit, and 55, 56, 57, 58 and 60 are output circuits.

In the configuration of FIG. 10, the signal waveforms shown in FIG. 11 are input to the input terminals 28, 29, 30, 38. The DCDDATA signal is input to the input terminal 28. This D
The CDDATA signal is a signal obtained by converting a magnetic signal into a binary signal.

The -DNDPPM signal is input to the input terminal 29. The -DNDPPM signal is a signal that becomes 0 for one system clock cycle for each 1-bit data obtained by converting a magnetic signal into a binarized signal.

The CLK signal (system clock signal) is input to the input terminal 30.

The -RST signal (reset signal) is input to the input terminal 38.

In FIG. 5, the falling period of the -DNDPPM signal indicates one bit of the DCDDATA signal. Therefore, the values are used as the -DNDPPM signal and DCDDAT in FIG.
Data "0" and "1" are indicated by the numbers between the A signals.

Here, time 10.5MS to 50.5MS
Then, a binary signal "11111110" is input.
If this is expressed in hexadecimal, it becomes FEH. Therefore, from time 50.5MS to 55.5MS, the output 8BDSCMP of the 8-bit comparator 34 becomes 1 and the output 8BOK of the D flip-flop 51 is inverted to 1. The 4-bit counter 40 (here, used as a 3-bit counter) increments for each 1-bit data while the 8BOK signal is 1 and outputs the 1-signal by the AND circuit 42 at the next 8th bit.

Next, from time 50.5 MS to time 90.5
Since the FEH signal is input by MS, the output 8BDSCMP of the 8-bit comparator 34 becomes 1 again,
Invert the D flip-flop 51 to 0 and set 16 BDS
CMP is set to 1.

When 16BDSCMP becomes 1, ID
The counter circuits 53 and 39 for counting the number of sentinels increment by one.

This ID sentinel counter circuit 53,
59 is incremented by 1 each time the ID sentinel is read once. Therefore, the control circuit 27 is shown in FIG.
By detecting the outputs 56 to 58, 60 of the circuit of
The number of D sentinels can be detected.

The circuit of FIG. 5 is initialized by setting the -RST signal to 0 for one system clock.

FIG. 12 is a circuit block diagram showing a fourth embodiment of the present invention, and FIG. 13 is a time chart showing the operation of the circuit of FIG.

Embodiments of FIGS. 12 and 13 and FIGS. 10 and 11
The difference between the embodiments is that the output 8BOK of the D flip-flop 51 of FIG. 12 is connected to the B4 input terminal of the 8-bit comparator via a knot circuit 62. Therefore, I
The D sentinel can correspond to an ID sentinel such as FEEEH in which the first 8 bits are different from the latter 8 bits. The operation is shown in FIG. According to FIG. 13, FIG.
The ID sentinel was FEFEH, but in FIG. 13, ID0 is 1 in FEEEH.

FIG. 14 is a circuit block diagram showing a fifth embodiment of the present invention. In FIG. 14, 63, 64, 69,
72, 73, 74, 75, 81, 84, 85, 86, 8
7,88 is a knot circuit, 65,71,76,77,7
8, 82, 89, 90, 91, 92, 93, 96 are AND circuits, 66 is a NOR circuit, 79, 83, 94 are OR circuits, 67 is a 4-bit shift register circuit (for example, SN74179 manufactured by TI), and 68 is A 4-bit comparator circuit (for example, SN7485 manufactured by TI), 70 is a 4-bit counter circuit (for example, SN741631 manufactured by TI, but is used as a 2-bit counter circuit in this example), 8
Reference numerals 0 and 95 are D flip-flop circuits, and 97 is an output terminal. 15 is a time chart for explaining the operation of FIG. In FIG. 15, the falling period of the −DNDPPM signal indicates one bit of the DCDDATA signal.
Therefore, the values are shown by numbers between the -DNDPPM signal and the DCDDATA signal in FIG.

In 0 to 20.5 MS, the value of FH is input to the 4-bit shift register 67 and the next 20.5 to
The output of the 4-bit comparator 68 is 1 for 25.5 MS.
Indicates that FH data was detected. Also, D
The value of the flip-flop 80 is inverted from 0 to 1, and it is stored that the 4 bits at the head of the ID sentinel are detected. From the next 20.5MS to 40.5MS, the EH data is input to the 4-bit shift register 67, and during the next 40.5MS to 45.5MS, the output 4BDCMMP of the 4-bit comparator 68 becomes 1, and the EH data is transferred. Indicates that it has been detected. However, at this time, the output of the D flip-flop 80 is 1 and the comparison input B0 of the 4-bit comparator 68 is 0.
EH was detected at S-40.5 MS.

At this time, the output 4 BDSCMP of the 4-bit comparator 68 and the output 4 of the D flip-flop 80
Since both BOKs are 1, the output 8BOK of the D flip-flop 95 is set to 1 in order to store that the 8 bits at the head of the ID sentinel are detected.

Next, between 40.5 MS and 60.5 MS, 4
The bit shift register 67 receives FH data,
The output 4BDSCMP of the 4-bit comparator 68 is set to 1 between 60.5 MS and 65.5 MS. Further, it is stored that the output 4BOK of the D flip-flop 80 is set to 1 and the output 8BOK of the D flip-flop 95 detects 12 bits from the head of the ID sentinel.

Finally, EH data is input to the 4-bit shift register 67 between 60.5 MS and 80.5 MS. Since the output 4BOK of the D flip-flop 80 is 1, the output 4BDSCMP of the 4-bit comparator 68 is 1. Therefore, 16BDSCMP becomes 1, indicating that the entire 16 bits from the head of the ID sentinel FEFEH has been detected.

Therefore, in the same manner as in the above embodiment, this 16BD
If the SCMP signal is counted, it is possible to count the number of ID sentinels.

[0092]

As described above, according to the present invention, the output signal of the control circuit 27 automatically holds 3 bytes of data after the ID sentinel, and the data can be sent to the control circuit 27 by serial communication. it can.

Further, it is possible to count the number of ID sentinels, hold the number, and similarly send data to the control circuit 27 by serial communication.

Therefore, since the processing of the control circuit 27 is simplified, the processing time of the control circuit 27 can be shortened.

Further, the latch circuit used in the detection circuit of the ID sentinel is 16 in the first and second embodiments.
However, in the third and fourth embodiments,
12 (8 bit shift register + 3 bit counter +
D flip-flops), and in the fifth embodiment, it could be reduced to 8 (4 bit shift register + 2 bit counter + D flip flop × 2).

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a time chart illustrating FIG.

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a block diagram illustrating an embodiment of the present invention.

FIG. 5 is a flowchart illustrating the embodiment in FIG. 4;

FIG. 6 is a circuit diagram illustrating a second embodiment of the present invention.

FIG. 7 is a circuit diagram illustrating a second embodiment of the present invention.

FIG. 8 is a time chart illustrating the embodiment of FIGS. 6 and 7.

FIG. 9 is a block diagram illustrating a second embodiment of the present invention.

FIG. 10 is a circuit diagram of an ID sentinel detection circuit showing a third embodiment of the present invention.

FIG. 11 is a diagram for explaining the operation of the circuit of FIG.

FIG. 12 is a circuit diagram of an ID sentinel detection circuit showing a fourth embodiment of the present invention.

FIG. 13 is a diagram for explaining the operation of the circuit of FIG.

FIG. 14 is a circuit block diagram showing a fifth embodiment of the present invention.

15 is a time chart explaining the operation of the circuit of FIG.

FIG. 16 is a perspective view of a conventional camera.

FIG. 17 is a block diagram of a conventional camera.

FIG. 18 is a flowchart of a conventional camera.

FIG. 19 is a diagram illustrating an information storage unit on a film used in a conventional camera.

FIG. 20 is a diagram illustrating an information storage unit on a film used in a conventional camera.

FIG. 21 is a diagram illustrating an information storage unit on a film used in a conventional camera.

FIG. 22 is a diagram illustrating an information storage unit on a film used in a conventional camera.

[Explanation of symbols]

1 Photographic lens 2 Lens actuator 3 Lens shutter 4 Photometric sensor for AE 5 Lens 6 Block including distance measuring sensor and viewfinder 7 Photoreflector 8 Film feeding motor 9 Gear train 10 Rewinding fork C Film cartridge F Film P ₁ , P ₂ Perforation 11 Pad 12 Pad advance / retreat control mechanism 16 Release button 17 Switch (SW1) for starting photometry and distance measurement 18 Switch for opening shutter and film feeding sequence (SW2) 20 Rewind switch 19 Back cover switch 21 ID Detection Circuit 22 Head Amplifier 23 Buffer 24 Decoder 25 Encoder 26 Buffer 27 Control Circuit 28 Motor Driver 128, 29, 30 Input Terminal 31 Knot Circuit 32, 33 Shift Regis 34,35 8-bit comparator 36 NAND circuit 37 Output terminal 38,39,40 Input terminal 41,43 4-bit counter 42 Not circuit 44,45,46,47,48 Output terminal 51,52,53,54,58,64 , 75, 80, 8
3,84 AND circuit 55,56,61,62,63,85,87 OR circuit 57 shift register 59,60 4-bit counter 65,68,69,70 input terminal 66,67,80 output terminal 71,74,76 , 77, 78, 86 knot circuit 72, 73, 77, 78, 86 D flip-flop

Claims (4)

[Claims] 1. A magnetic head for writing and reading information to and from a magnetic storage unit provided in a film, a film feeding means for feeding a film, and a film feeding means for feeding the film after the filming is completed. A write instruction means for driving the magnetic head therein to overwrite the camera information on the film information previously written in the magnetic recording portion of the photographed frame, and to index one frame of film When a film cartridge containing a partially used film is reloaded, the film feeding means starts the film winding and the magnetic head is driven to perform the frame indexing. An exposure state determining means for detecting whether or not the film information is still written in the magnetic storage portion of the frame indexed by the means, and determining whether the frame is exposed or not. In a camera using the provided film with a magnetic recording unit, a circuit for detecting the film information is constituted by a shift register circuit and a comparison circuit. 2. A film in which a number of pieces of film information, which are larger than the number of pieces of camera information written by a magnetic head after the end of photographing, is preliminarily written in the magnetic storage portion of each frame is used in the exposure state determination means. When a film cartridge containing a partially used film is reloaded, a circuit is provided to count the number of pieces of film information that have been written in the magnetic memory of the frame indexed by the frame indexing means. A camera characterized by that. 3. The camera according to claim 2, wherein the other film information after detecting the film information is held in the shift register circuit or the number of film information is held in the shift register circuit, and the film information is output to the external circuit from the shift register circuit. A camera provided with a circuit for outputting the information of. 4. A magnetic head for writing and reading information to and from a magnetic storage unit provided in a film, a film feeding means for feeding a film, and a film feeding means for feeding the film after the filming is completed. The magnetic head is driven therein, and a writing instruction means for overwriting the camera information on the film information previously written in the magnetic storage portion of the photographed frame and indexing one frame of the film are performed. When a film cartridge containing a partially used film is reloaded, the film feeding means starts the film winding and the magnetic head is driven to perform the frame indexing. An exposure state determining means for detecting whether or not the film information is still written in the magnetic storage portion of the frame indexed by the means, and determining whether the frame is exposed or not. In a camera using the provided film with a magnetic storage unit, the circuit for detecting the film information is composed of a shift register circuit, a comparison circuit, a storage circuit, and a counter circuit having a bit length shorter than the bit length of the film information. A film information detection circuit characterized by: