JPH0823653B2 - Camera with film information reader - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a camera having a film information reading device, and in particular, a film in which film sensitivity information and film number information are coded and arranged. The present invention relates to a camera having a film information reading device that detects the number of films by using a so-called DX film.

[Background of the Invention]

In recent years, many cameras use a motor to feed the film, and those that automatically rewind the film by detecting the end of the film are commercially available.
However, when the film is fed at a high speed, when the film is wound to the end, a high mechanical tension is applied, which causes a problem of durability of the feeding mechanism of the camera, especially gears. In addition, depending on the film manufacturer, when winding the film around the Patrone shaft, conventionally there was also one that produced no problem even if tension was applied with adhesive tape, but recently there is a method of simply making a hole in the film and hooking it on the Patrone shaft. Things are becoming more and more prominent, and in this case, if the film is strongly wound up, there is a possibility of a fatal problem that the film hole is broken and the film is exposed from the patrone.

In the case of using a so-called DX film in which information about the number of sheets is provided in the film cartridge, the above problem does not occur if the film is photographed up to that number and the film is automatically rewound immediately.

 First, such a DX film will be described.

FIG. 3 is a side view showing a patrone of DX film, and FIG. 4 shows a DX code arranged in the patrone shown in FIG. In the DX code shown, the white part represents the conductive part and the black part represents the non-conductive part. A contact (not shown) corresponding to the above DX code is provided in the cartridge storage portion of the camera body. 1,2,3,4,5,6 in the code shown
Is an ISO sensitivity information detection area of the film, and among these areas, 1 is a ground area. Further, 7,8,9,10 are the number detection areas, 11,12 are the latitude detection areas, and 7,8 are the ground areas.

Table 1 below shows the binary code assignments in the ISO speed code.

In the above table, it can be seen that the contacts in areas 5 and 6 never turn off.

Next, Table 2 shows the allocation of the binary code in the film number code.

In this way, 3 bits are allocated for the number of films with the DX code, but normally used films are 12Ex, 20Ex, 24Ex, 36Ex, so even if the 3rd bit is not used. , Almost no problem. That is,
In Table 2, use 8 and 9 and not use 10 without any problem.

[Object of the Invention]

An object of the present invention is to use the third bit which does not need to be used in a camera having a film information reading device for detecting the number of films by using a standard DX film which is assigned 3 bits to detect the number of films. Provided is a camera having a film information reading device capable of reducing the mounting space and the cost of the camera by reading the number of films without doing so and determining whether or not the DX film is contained by other means. Especially.

[Outline of Invention]

A camera having a film information reading device according to the present invention is a camera having a film information reading device for reading film information from a film cartridge having at least a 3-bit film number information code part and a multi-bit film sensitivity information code part. First detecting means for detecting the number of films by only the 2 bits, which is the film number information code part and may output the same detection result as in the case of a cartridge having no coded information. And a second detecting means for detecting whether or not the cartridge has information coded by the film sensitivity information code section.

Example of Invention

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments shown in the drawings.

 FIG. 1 shows an embodiment of the present invention.

The apparatus shown in FIG. 1 obtains logarithmic compression information BV corresponding to the brightness of the object by the side light circuit including the light receiving element SPC, the operation amplifier OP1, and the compression diode D1, and this and the ISO sensitivity detection device DXSV of the film. The sensitivity value SV from the manual sensitivity setting device MSV or the sensitivity information SV from the manual sensitivity setting device MSV and the setting information TV from the variable resistor VR2 linked with the shutter dial are calculated by the calculation amplifier OP2, and the aperture value AV generated as a voltage is calculated. The aperture is controlled by the aperture control magnet MG1 while displaying on the display device DSP in the viewfinder. In the figure, DAC is a DA converter that converts the information from the ISO sensitivity detector into analog voltage, SWSV is manual and D
X changeover switch, VG1 is a constant voltage source, OP2 is an operational amplifier that calculates the aperture value by BV + SV-TV, ADC is an AD converter that converts the aperture value AV into a digital value, and DCD is a decoder driver for the display. Also, CNT is a counter, AEFP is a comb-shaped electrode, and BR is its brush.When the diaphragm of the lens is narrowed down, the brush BR runs at the same time, the signal is input to the counter CNT, and the diaphragm is actually narrowed down. Counter CN
It is counted as the count value of T. DCMP is a digital comparator, which is transmitted to one input of the counter CNT, the digital value of the calculated aperture information is transmitted to the other input from the AD converter ADC, and when both match, the output of the digital comparator DCMP is output. This signal becomes 0 level, and this signal turns off the transistor TR1 via the resistor R6 to supply the current of the diaphragm control magnet MG1 to stop the narrowing. In this way, the actual control of the calculated aperture is performed.

MG2 is the first tension magnet, and when it is driven,
A known camera mechanical sequence is executed, and the above-mentioned aperture control is first performed.

MG3-1 is a lock release magnet of the shutter front curtain,
By energizing this, the shutter front curtain starts running. The switch SWT is a count switch related to the running of the front curtain, is normally closed, and opens according to the running of the front curtain. The variable resistor VR1 and the capacitor C1 form an integrating circuit that operates when the count switch is open. resistance
VR1 is mechanically coupled to the variable resistor VR2, and is set to a resistance value according to the set shutter speed. CP
Reference numeral 1 is a comparator, one of the inputs of which is connected to the above integrated voltage, and the other input of which is connected to the power supply voltage Vcc by resistors R4 and R5.
The voltage divided by is connected. Therefore, the output of the comparator CP1 is controlled by the time-determining circuit determined by the resistor VR1, and becomes 1 level after the shutter time has elapsed, and becomes 0 level for a certain time by the one-shot circuit ON1, and the shutter rear curtain magnet MG3− Energize 2 to drive the rear curtain of the shutter.

This device is provided with a total of three motors for film winding, film rewinding, and charge system. MB is a film winding motor, DB is its driving circuit, MC is a film rewinding motor, DC is its driving circuit, MD is a charging motor, and DD is its driving circuit.

In addition, as mentioned above, DXFLM is a film number reading device that reads the number of films of DX film that is arranged by encoding film sensitivity information and film number information in the film cartridge, LED does not use DX coded film In case of failure, a warning indicator to warn of this is shown.

A microcomputer COM is provided to control the operation of the camera. BAT is its power battery, TRBAT is a power transistor, and the above static circuit operation is performed only when the power transistor TRBAT is ON.

In this microcomputer, X0 and X1 are terminals connected to a crystal oscillator QZ that supplies a basic clock, RST is a reset terminal, V _DD is a power supply terminal, and GND is a ground terminal.

As an input port, the input port PA0 from the switch SW1 that turns on with the first stroke of the release button, the input port PA1 from the switch SW2 that turns on with the second stroke of the release button, and on when the mirror is down. Input port PA2 from the mirror switch MRUP, input port PA3 from the switch CN2 that turns off when the rear curtain of the shutter runs and turns on when charged, and switch FLM1 that turns on and off with film winding. Input port PF0, input port PF1 from switch FLM3 that is interlocked with the sprocket and turns on when one frame has finished winding, input port PF2 from switch CGE that turns on when shutter, automatic aperture, and mirror charging complete, Input ports PG0, PG1 connected to the film number reader DXFLM, input port PG2 connected to the film ISO sensitivity detector DXSV, Input ports PG3 connected to the output of the Le comparator DCMP is provided. In addition, the microcomputer COM has an input port PG4 from the cartridge presence / absence switch PT, a connection port PG5 from the camera back lid opening / closing switch BP (OFF when closed), and a film cassette for all films at the end of film rewinding. Switch RSTP (ON to turn on the former, OFF to turn to the latter. This switch can be attached to the outside of the camera and selected by the photographer, or An input port PG6 from a wiring pad or a printed board on the printed board may be provided inside the camera so that it can be set at a service station or the like according to the photographer's preference.

Also, as an output port, a resistor R7 and a transistor
Via the output port PE0 connected to the first tension magnet MG2 via TR2, the resistor R8 and the transistor TR3, via the output port PE1 connected to the first curtain magnet MG3-1, the inverter I1 and the resistor R10, Power transistor TRBAT
An output port PE3 connected to the DX code warning indicator LED is provided through an output port PE3 connected to the counter CNT, an output port PE4 connected to the reset input RST of the counter CNT, an inverter I2 and a resistor R11. Also, motor MB,
Output ports PB0, PB1, PC0, PC1, PD0, PD1 connected to the drive circuits DB, DC, DD of the MC, MD respectively are provided.

FIG. 2 shows details of the drive circuits DB, DC, DD of the motors MB, MC, MD. Since these drive circuits are exactly the same, FIG. 2 shows a circuit common to them. In the figure,
M is a motor, A and B are inputs, I10 and I11 are inverters, and A10 and A1
1, A12 is AND gate, OR10, OR11 is OR gate, TR30, T
R31, TR32, TR33 are transistors, R30, R31, R32, R33, R34, R
35 and R36 are resistors and D10 and D11 are diodes.

The inputs A and B are 2-bit information, and if A = 1 and B = 0 first, the output of the AND gate A12 becomes 1 and the output of the OR gate OR10 also becomes 1 and the transistor TR32 turns ON. Further, the output of the inverter I13 becomes 0, so that the transistor TR31 also turns on. Therefore, the motor M has a power supply Vcc
From the transistor TR31, the motor M, and the transistor TR32, a current flows to rotate the motor.

When A = 0 and B = 1, the output of the AND gate A10 becomes 1, the output of the OR gate OR11 becomes 1, and the output of the inverter I12 becomes 0, so that the transistors TR30 and TR33 become
When turned on, the motor rotates in the opposite direction to the above-mentioned rotation.

When A = 1 and B = 1, the output of AND gate A11 becomes 1 and the output of OR gates OR10 and OR11 becomes 1
Then, the transistors TR32 and TR33 are turned on. Therefore, if this input mode is set while the motor M is rotating, whichever the motor is rotating by the diodes D10, D11 and the transistors TR32, TR33, the current from the power source Vcc is lost and the motor is inertial. When the motor continues to rotate, the short-circuit brake is applied to the motor.

When A = 0 and B = 0, AND gates A10 to A12
Output of all becomes 0, transistor TR30, TR31, TR32, T
All R33 are turned off and the motor is opened.

Next, the operation of the above microcomputer will be described with reference to the flowcharts shown in FIGS.

The microcomputer COM operates when V _DD is applied to the power supply terminal V _DD . First, the basic clock is supplied by the crystal oscillator QZ connected to the terminals X0 and X1, and at the same time, the capacitor C connected to the reset terminal RST. _The power-on reset is applied to the microcomputer COM by _RST , the program counter is initialized to the address 0, and the program starts from START. Further, each flag is set to 0 and the output port is also set to 0.

 First, the main routine shown in FIG. 5 will be described.

[Step (1)] Sense input port PA0. Switch S
W1 is the first stroke of the release button, and the switch SW1 is turned on by pushing. If the switch SW1 is ON, go to step (2), otherwise go to the autoloading routine. A description of autoloading is omitted.

[Step (2)] PE3 = 1. Set output port PE3 to 1. This signal turns on the power transistor TRBAT described above via the inverter I1 resistor R10 and supplies the voltage Vcc to the power sources of all circuits such as the operational amplifier and the AD comparator.

[Step (3)] Sense input ports PA0 to PA3. These input ports PA are the switch SW1, the switch SW2 which is turned on by pressing the second stroke of the release button, the switch MRUP which is turned on when the mirror is down, and the shutter rear curtain. Switch CN2 is connected which turns off when turned on and turns on when charged. If any one is turned off, step (1)
Return to and when all are ON, input port PA is 16
Since it is 00H in decimal, proceed to step (4).

[Step (4)] Set the output port PE4 to 1 and then to 0. Output port PE4 is reset input RST of counter CNT
The counter CNT is reset by this instruction.

[Step (5)] The output port PE0 is set to 1, and after a certain time has passed (TIME1), the output port PE0 is set to 0. Transistor TR2 is connected to output port PE0 via resistor R7.
Is connected, a current is applied to the first tension magnet MG2 for a certain period of time, and the release sequence of the camera is performed. When the first tensioning is driven, a known camera mechanical sequence such as a diaphragming operation and a mirror-up operation is started, and diaphragm control is first performed. At the same time when the diaphragm of the lens is narrowed down, the brush BR that displaces the comb-teeth electrode AEFP in conjunction with the diaphragm runs. Since this signal is input to the counter CNT described above, the value that the diaphragm is actually narrowed down is counted as the count value of CNT.
The output of the counter CNT is transmitted to one input of the digital comparator DCMP. The other input of the digital comparator DCMP is the digital value of the calculated aperture information, AD
Since they are connected to the output of the converter ADC, the output of the digital comparator DCMP becomes 0 level when they match. This signal turns on transistor TR1 via resistor R6.
By performing FF, the current of the diaphragm control magnet MG1 is supplied, and the locking member (not shown) is activated to lock the diaphragm mechanism and stop the narrowing. The actual control of the aperture calculated in this way is performed. The output of the digital comparator DCMP is transmitted to the input PG3 of the microcomputer COM.

[Step (6)] TIME2 This is a fixed time timer.

[Step (7)] Sensing the input port PA2. It is a sense of whether or not the mirror is up. First tension magnet
By the operation of MG2, narrowing down and mirror up are performed almost at the same time. The mirror-up time is almost constant, but the aperture time varies depending on the aperture value.

[Step (8)] Discrimination of flag F0.

[Step (9)] Discrimination of flag F1. Step (8),
(9) Since the flag is 0 as a result of the power-on reset, the program proceeds to step (10).

[Step (10)] The output port PE1 is set to 1 and set to 0 after a fixed time (TIME3). The transistor TR3 is connected to the output port PE1 via the resistor R8, and the shutter front curtain magnet MG3-1 is energized for a certain period of time. This causes the shutter front curtain to run. When the front curtain of the shutter runs, the count switch SWT is opened. This causes the resistance VR1
And an integrating circuit consisting of a capacitor C1 operates. resistance
VR1 is mechanically connected to the resistor VR2, and the resistance value will be selected according to the set shutter speed. The integrated voltage is connected to one input of the comparator CP1, and the power supply voltage Vcc and the voltage separated by the resistors R4 and R5 are input to the other input. Therefore, the output of comparator CP1 is resistor V
It is controlled by the time of the timing circuit determined by R1, and becomes 1 level after the shutter time has elapsed and becomes 0 level by the one-shot circuit ON1 for a certain period of time, and the shutter rear curtain magnet MG3-2 is energized Run the curtain.

[Step (11)] Sensing the input port PA3. The trailing-curtain detection switch CN2 is a switch that is turned off when the trailing-curtain of the shutter is completed, and this branch command is a routine to wait for the end of the shutter operation. When the trailing curtain has finished running, the operation proceeds to step (12).

[Step (12)] This is an instruction to branch by the shooting number counter FCNT (details will be described later). If the number of recordable frames FEX of the film and the number of captured images FCNT become equal, the film rewinding routine RWND proceeds, and if they do not match, the process proceeds to step (13).

For example, if you take 36 sheets of film and take 36 sheets, go to rewind RWND and rewind the film automatically (auto rewind).
I do.

[Step (13)] The content of the shooting number counter FCNT is incremented by one. The initial setting of the number of shots counter FCNT is the film auto-loading routine AL described later.
Is set to 1.

[Step (14)] Output instruction to output ports PD0 and PD1, P
D0 = 0, PD1 = 1 By adding this signal to the drive circuit DD, the charging motor MD rotates and the shutter, mirror,
The automatic aperture is charged.

[Step (15)] PB0 = 0, PB1 = 1 The film winding motor MB is rotated in the same manner as in step (14).

[Step (16)] Timer for timer interrupt
Set a constant K in TMR. The value of K is determined by the film winding speed and the comb speed pattern for detecting the film speed connected to the sprocket and the instruction cycle time of the microcomputer, and is described here as a constant K.

Start the timer for the timer interrupt (START TMR). Enable timer interrupt (E
NT). Input the constant M into the internal register RG. Flag F0
Set = F2 = 0 and F1 = 1. Since the timer has started, the timer then repeatedly decrements independently of the program routine, interrupts are applied at fixed time intervals (depending on the constant K), and the program being executed shamps to a dedicated timer interrupt address. The timer interrupt routine will be described with reference to FIG.

"Timer interrupt routine" [Step (101)] STOP TMR DIST Disables timer decrement operation and interrupt.

[Step (102)] A signal from a switch FLM1 including a comb tooth for film speed detection and a brush connected to a sprocket is input at the input port PF0.

If PF0 is 0 (switch ON), go to step (103), 1
If it is (switch OFF), proceed to step (109).

[Step (103)] Discrimination of flag F2. Steps (16)
Since F2 = 0, the process proceeds to step (104).

[Step (104)] RG = RG = 1. The contents of the internal register RG are decremented by 1 and the contents are stored again in RG.

[Step (105)] Determine whether RG has become 0. In the programs up to the present, M-1 is the content of RG, so if M is a large value to some extent now, it will not become 0, so proceed to step (106).

[Step (106)] 1 interlocked with sprocket
Input the signal of pattern switch FLM3 which indicates the end of winding the frame. Since it is not near the end here, step (10
Proceed to 7).

[Step (107)] The constant K is reset in the timer register, the timer is started, and the interrupt is enabled.

[Step (108)] Return to the original program being executed.
The timer interrupt is intended to determine the signals of the switch FLM1 and the switch FLM3 from the running program at regular intervals. Since the program itself executes each instruction at a very high speed, the film winding information is sensed at regular time intervals and there is practically no problem.

Now, if the comb pattern switch FLM1 is turned off by a certain timer interrupt, the interrupt routine proceeds from step (102) to step (109).

[Step (109)] Sense flag F2. step 1
Since the flag F2 = 0 was set in step 6), step (1
Go to 10).

[Step (110)] F2 = 1. Set flag F2 to 1. This means that the switch FLM1 is OFF, that is, PF0 has changed to 1. For the same purpose, there is a step (112) meaning that PF0 has changed to 0.

[Step (111)] RG2 = M. The constant M is set again in the internal register RG2. Thereafter, the process proceeds to step (106) to execute the above routine.

When the motor MB is energized and the winding of one frame is completed, the switch FLM3 is turned on according to the completion pattern.
In the timer interrupt routine at this time, the program proceeds from step (106) to step (113).

[Step (113)] PB0 = 1. Since PB1 is also 1, the film motor MB is braked.

[Step (114)] F1 = 0. Set flag F1 to 0. This is a flag indicating that the film winding is completed. Next, in step (108), the program being executed is returned to. Since step (107) is not passed here, the timer interrupt will not be applied again thereafter.

Next, let's think about the case when, for example, a film without a code for the number of films for 24 shots is used and the shooting of 24 frames is completed. The camera tries to wind the film with the winding motor MB, but since the film cannot move any more, the ON-OFF signal of the switch FLM1 does not change. The program always proceeds from step (103) or step (109) to step (104). In step (104), RG is decremented by 1 as described above, so that in some timer interrupts, RG finally becomes 0 in step (104). Therefore step (10
The program branches from step 5) to step (115).

[Step (115)] PB0 = 1, PB1 = 0. Both terminals of motor MB are opened.

[Step (116)] F0 = 1. Set flag F0 to 1. This means the film is finished.

This completes the explanation of the timer interrupt routine, but this interrupt is always executed from step (16) of the main routine to step (9) of the next shooting, and the film winding control is executed accurately. To do.

 Next, the main program routine will be described again.

[Step (17)] Input port PF2 sense. this is,
It is a routine that waits until the switch CGE is turned on, that is, the charge is completed by receiving the signal from the charge switch CGE indicating that the shutter, the automatic aperture, and the mirror have been charged. If the charge is undecided, the step (1
Return to 7) and proceed to step (18) when completed. Of course, many timer interrupts are applied during this period.

[Step (18)] PD0 = 1. Outputs 1 to output port PD0. The charging motor MD is braked.

[Step (19)] A flag F0 indicating the end of the film is sensed by a timer interrupt. If the film is not finished, go to step (20).

[Step (20)] Input port PA sense. Similar to step (3). When the photographer continuously shoots, the switch SW2 continues to be ON, and the input port PA becomes 00H in hexadecimal, so the process proceeds to step (21).

[Step (21)] 1 is output to the output port PE4, and 0 is subsequently output. Similar to step (4) described above, the counter CNT is reset.

[Step (22)] As in the step (5), the first tension magnet MG2 is energized to start the next release sequence. At this time, the film winding may be continued. This flowchart is designed to maximize the number of frames that are continuously photographed within a fixed time, so the next release sequence is started without waiting for the end of film winding.

[Step (23)] As described above, when the first tightening is started, the narrowing operation is performed. Digital comparator
The output of DCMP becomes 0 when the narrowing control is completed, so if the input port PG3 is sensed, it is possible to know whether the narrowing is completed. Step (23) is this branch instruction, and when the narrowing down is completed, the process proceeds to step (7).

After confirming the mirror-up in step (7), the completion of film winding is confirmed in step (9). Until then, the timer interrupt is repeated many times, and if the winding is completed, the process proceeds to the next shutter control. When the film winding is not completed yet at step (9), the loop from step (8) is repeated until the film winding is completed by the timer interrupt. The above is the routine for continuous shooting.

If the film winding is designed to be completed during diaphragm control when the battery is new, the waiting time in step (9) can be eliminated and the frame speed can be maximized.

Next, shooting of only one frame will be described. After shooting one frame, the photographer should not have pressed the second stroke of the release button, so the program proceeds from step (20) to step (24) until the timer interrupt routine senses the completion of winding. That is,
The loop of steps (24) to (19) is repeated until F1 = 0. When winding is completed, the process returns from step (24) to START.

Next, let us consider the case where the film ends in the middle of winding. When a film with a DX code is used, the number of shots FCNT and the number of shootable frames FEX are compared in step (12), so the film will not end during winding, but DX It occurs when there is no code on the film or when the photographer cuts and uses the film. When the film is finished during the winding process, the flag F0 is set to 1 during the timer interrupt process. Therefore, the process proceeds from step (19) to the rewinding routine RWND.

Next, the rewinding routine RWND will be described with reference to FIG. Film rewinding in step (12)
This is performed when FCNT = FEX and when F0 = 1 in step (19).

[Step (30)] PC0 = 0, PC1 = 1. Output command to output port PC. By this command, the film rewinding motor MC is rotated from the PC port via the drive circuit DC.

[Step (31)] The constant M1 is assigned to the internal register RG.

[Step (32)] Input port PF0, that is, switch FLM
It's a sense of 1. Switch F for film winding
Input the ON-OFF signal of LM1, that is, the switch consisting of the comb-shaped pattern and brush that are interlocked with the sprocket.

[Steps (32) to (39)] This step includes the steps (102), (103), (104), (105), (109),
It is similar to the program for detecting the film movement described in (110), (111), and (112). It is a program that detects that the sprocket does not rotate when the film rewinding is completed. At the end, the program proceeds from step (35) to step (40).

[Step (40)] Sense input port PG6. The input port PG6 is connected to a switch RSTP that selects whether the film is completely wound in the cartridge or only the leader is left at the end of film rewinding. If the switch RSTP is turned ON, the former will be used. If it is turned OFF, the latter will be used. When turned on, the program proceeds from step (40) to step (41).

[Step (41)] TIME4 Command to wait a fixed time. Even if the sprocket stops, the rewinding motor MC continues to rotate, and the film is all wound into the cartridge.

[Step (42)] PC0 = 1. Brakes the rewind motor. PC1 is 1, so after that the program is S
Return to TART.

When film is rolled up, switch FLM1 is turned on
-OFF Wait a fixed time (TIME4) after the end of repetition and stop the motor, and leave the reader unit, switch FL
Stop the motor immediately after the M1 ON-OFF cycle ends. Since the switch FLM1 is a switch dependent on the sprocket, even if the leader is left, the perforation of the leader does not get caught on the sprocket claw, and the film cartridge can be taken out safely.

[Step (24)] PD0 = 1, PD1 = 1. The charge motor MD is rotationally driven by an output command from the output port PD.

[Step (25)] Sense input port PF3. (Switch CGE) Input of charge completion signal. If the charge is not completed, the process returns to step (25). If the charge is completed, the process proceeds to step (26).

[Step (26)] PD0 = 1. Set the output port PD0 to 1. Therefore, the charging motor is braked. Since the mirror is charged in this state, the mirror goes down and returns to the initial state. Next, the program jumps to RWND, that is, step (30), and the film rewinding routine described above is performed.

Next, consider the case where the switch SW1 is off at START. At this time, the auto loading AL shown in Fig. 8
The program advances to.

[Step (50)] First, the power transistor TRBAT is turned off.
And the power supply Vcc is cut off.

[Step (51)] Sense input port PG5. PG5 is connected to the back cover opening / closing switch BP of the camera, and is turned off when the back cover is closed and turned on when the back cover is open. When the back cover is closed, return to START. If it is open, proceed to step (52).

[Step (52)] PG again with the back cover open.
5, sense switch BP. If it remains open, then step (52) is performed again and the program does not proceed here. This means that the camera does not move when the back lid is open. When the back cover is closed in step (52), the process proceeds to step (53).

[Step (53)] Sense input port PG4. A switch PTIN for determining whether or not there is a cartridge is connected to PG4. If there is no cartridge, it is turned on, so return to START, and if it is, proceed to step (54) to automatically load the film.

[Step (54)] PE3 = 1. Power supply Vcc is applied to each circuit as in step (2).

[Step (55)] Sense input port PG2. If the film does not have a DX code, the DX code detector DX
The NONDX signal (1 level) is output from the SV. The NONDX signal is also output when reading a code that is not used due to some defect despite using the DX coded film. In this case, proceed to step (57). When you read the DX code, proceed to step (56).

[Step (56)] The output port PE5 is set to 0. Due to the inverter I2 resistance R11, the DX code warning indicator LED does not light up (no warning is given).

Read the film number code from input ports PG0 and PG1. The DX film number code has 3 bits as will be described later, but here 2 bits are input considering the film that is normally used. The number of sheets is judged by this code, and the number of sheets is stored in the FEX register.

[Step (57)] Output 1 to the output port PE5 to turn on the indicator LED to warn. If the photographer does not use the film with DX code, the switch SV
To operate the member for setting the film sensitivity by manual setting (MSV). In case of DX film, put it in the camera again to avoid reading mistakes.

When the program proceeds to step (57), 36 is set in the film number register FEX. Therefore, when such a film is used, it is not possible to shoot more than 36 sheets.

[Step (58)] ALG1 = 0. Initially set FLM1 count register ALG1 for autoloading to zero.

[Step (59)] PB0 = 1, PB1 = 1. The film feeding motor is rotated in the opposite direction to that during normal feeding. This causes the sprocket to rotate and the film to enter the spool. It is assumed that the gear ratio of the sprocket and the spool is determined so that the film is wound by the rotational force of the spool when wound on the spool.

[Step (60)] Input port PF0 sense. Switch F
If LM1 is on, proceed to step (61), and if LM1 is off, return to step (60).

[Step (61)] Sense input port PF1. The switch pattern FLM3 provided for each frame is sensed. FLM3
If it is OFF, proceed to step (62).

[Step (62)] The register ALG1 initially set in step (58) is incremented by 1.

[Step (63)] Sense PF0 again. Steps (60)
Since the switch FLM1 was turned on, wait for it to turn off here and then return to step (60).

The routine of steps (60) to (63) is such that when the photographer inserts the film into the camera, the camera feed is switched even though the ON phase of the switch FLM3 is not fixed.
Since it is configured to feed one frame when FLM3 is ON, it may not be possible to feed up to 36 films with 36 shots if autoloading is sent with a fixed number of frames. Then, it is necessary to count how many times the switch FLM1 is turned ON and OFF until the switch FLM3 is turned ON. The program runs from step (61) to step (6
When proceeding to 4), the ON / OFF count of the above switch FLM1 becomes AL.
Counted to G1.

[Step (64)] If the content of the register ALG1 is larger than the constant P, the process proceeds to step (66). If it is less than P, the process proceeds to step (65).

[Step (65)] When P or less, the automatic loading frame number counting register ALCNT is set to 0.

[Step (66)] When it is larger than P, the autoloading frame number counting register ALCNT is set to 1.

[Step (67)] Switch FLM3 is turned on in step (61).
Because it was doing, it is a routine to wait for it to turn off.

[Step (68)] Next, a routine for waiting for the switch FLM3 to be turned ON. Therefore, step (68) to step (69)
When the program proceeds to, it means that one film has been sent from step (61).

[Step (69)] The register ALCNT is incremented by 1.

[Step (70)] If the register ALCNT does not become 4, the process returns to step (67) to repeat the above routine. Four
When it becomes, proceed to step (71).

The steps (64) to (70) above are for feeding three frames next when the number of ON-OFFs of the switch FLM1 is counted from the start of autoloading until the switch FLM3 is first turned ON, When the number of FLM1 ON-OFF counts is small, the next four frames are fed.

[Step (71)] PB1 = 1. Brakes the film motor.

[Step (72)] FCNT = 1. Register for counting the number of shots
Set FCNT to 1. At this point, the auto loading routine is completed and the process returns to START.

〔The invention's effect〕

As described above, according to the present invention, the number of films is detected only by 2 bits of the 3-bit film number information code, so that the mounting space of the camera can be reduced and the cost of the camera can be reduced. In addition, since it is possible to detect whether or not it is a patrone provided with coded information from the film sensitivity information in performing the above detection, erroneous sheet number information from a patrone without such information is provided. Accurate number information can be obtained without being mixed.

[Brief description of drawings]

1 is a block diagram of a circuit for carrying out the present invention, FIG. 2 is a circuit diagram showing a drive circuit of the motor shown in FIG. 1, and FIG. 3 is
FIG. 5 is a side view showing the patrone of the DX film, FIG. 4 is a view showing the DX code arranged in the patrone shown in FIG. 3, and FIG.
FIG. 6, FIG. 7, FIG. 7 and FIG. 8 are flowcharts showing the operation of the microcomputer shown in FIG. SPC: Photodetector OP1, OP2: Computational amplifier DXSV: ISO sensitivity detector MSV: Manual sensitivity setting device DSP: Aperture display device SWSV: Changeover switch DXFLM: Film number reader DCMP: Digital comparator CNT: Counter AEFP: Comb tooth -Shaped electrode MG1: Aperture control magnet MG2: First tension magnet MG3-1: Shutter front curtain lock release magnet MG3-2: Shutter rear curtain magnet

(72) Inventor Masayuki Suzuki, 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc. Tamagawa Plant (72) Inventor, Keisho Ohara 770, Shimonoge, Takatsu-ku, Kawasaki, Kanagawa Prefecture In-house (72) Yoichi Tosaka, 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc. Tamagawa Plant (56) References JP-A-60-212745 (JP, A) JP-A-60-28634 (JP, A) ) JP-A-60-208737 (JP, A)

Claims (1)

[Claims] 1. A camera having a film information reading device for reading film information from a film cartridge having a film number information code portion of at least 3 bits and a film sensitivity information code portion of a plurality of bits,
First film detecting means for detecting the number of films by only 2 bits, which is the film number information code part and may output the same detection result as in the case of a cartridge having no coded information. A camera having a film information reading device, further comprising a second detecting means for detecting whether or not the cartridge has information coded by the film sensitivity information code section.