JPS58223127A - Film information reader of camera - Google Patents

Abstract

PURPOSE:To detect securely only a film information hole, by providing a light emitting element in a sprocket for advancing a film and guiding light emitted from the element through a light guide hole perforated in the sprocket centripetally. CONSTITUTION:The light emitting element 8 is provided in the sprocket 7 which is provided on the film take-up side of a camera body 6, and advances the film 11 by hooking an advance pawl 7a in a perforation 11b of the film 11. The light emitted from the element 8 is guided out of the sprocket 7 through plural light guide holes 7b perforated in the sprocket 7 centripetally and photodetected through information holes 11c of the film 11. The principal part consists of a photodetecting element 9 for code reading provided on a camera back 10 and a sprocket rotation detection switch SW2 which engages the advance pawl 7a and generates a synchronizing signal for controlling the information read timing of the photodetecting element 9.

Description

DETAILED DESCRIPTION OF THE INVENTION More specifically, the present invention relates to a film information reading device for a camera that detects film information holes formed in a film and reads film information such as film sensitivity and the number of frames that can be photographed.

By providing perforations other than perforations on the film, and providing film information such as film sensitivity and the number of frames that can be taken, depending on the position and number of perforations, and detecting the position and number of perforations. , films and film information reading devices that can read film characteristics as code information are already known (%
(Refer to Publication No. 57-41619).

By the way, as shown in FIG. 1, the conventional roll film l having film information holes has a perforation l.
In order to prevent confusion between the film information hole IC and the film information hole IC, a circular film information hole 1c, which is smaller than the perforation lb, is provided closer to the side edge than the position where the rectangular perforations lb are arranged. , are sequentially and selectively drilled over a predetermined length range. A conventional film information reading device that reads film information from the film 1 includes a light emitting element 2 and a light receiving element 3 for detecting an information hole, which are arranged so as to face each other with the film information hole 1c interposed therebetween; The main part thereof was composed of a light emitting element 4 and a light receiving element 5 for generating an information read synchronization signal, which were arranged so as to be opposed to each other with a perforation lb interposed therebetween. This film information reading device
The perforation ib moves as the perforation ib is fed, and when it corresponds to between 4 and 5 pixel elements, a synchronization signal is generated.In response to this synchronization signal, the light emitting element 2 for detecting the information hole is activated. The presence or absence of the film information hole IC to be located between the light receiving elements 3 is detected based on the photoelectric conversion output of the light receiving elements 30. In this way, the presence or absence of the information hole 1c is sequentially detected over a predetermined length range of the film l, and the information hole I obtained thereby is detected.
The permutation of the presence or absence of C was read as code information representing film information.

However, in the above conventional roll film 1 and film information reading device having the film information holes 1c, the film information holes lc are bored closer to the side edge than the perforations 1b arranged in a row closer to the side edge of the film l. Therefore, due to positional deviation or mounting error when the roll film 1 is mounted on the camera, the light receiving element 3 for detecting the information hole may detect the perforation lb, or the light receiving element 5 for generating the synchronization signal may detect the perforation lb. There was a high risk that the IC would be detected and malfunction would occur.

Therefore, as shown in Fig. 2, the film information hole 11c was bored at the same height as the perforation llb, and between the adjacent perforations 1it).
Roll film 1 with new film information hole 11c
1 has been proposed, but such a roll film 11
As a film information reading device for a camera using a perforation l
Two pairs of light emitting elements 2, 4 and a light receiving element 3 are arranged so as to be able to face each other via the film information hole 11c.
, 5 has been proposed. This film information reading device focuses on the difference in size between the perforation llb and the film information hole 11C, and identifies the difference in the level of photoelectric conversion output in the light receiving element 3.5. I tried to distinguish between However, due to reasons such as the fact that the feeding speed of the film 11 is not constant, it is unavoidable that the perforation llb and the information hole 11c may be mistakenly confused, resulting in a drawback that there is a high risk of malfunction.

In view of the above-mentioned points, an object of the present invention is to arrange a light emitting element in a film feeding sprocket, and to direct the light emitted from the light emitting element to the outside through a light guide hole formed centripetally in the sprocket. Therefore, it is an object of the present invention to provide a film information reading device for a camera that can reliably detect only film information holes.

Hereinafter, the present invention will be explained based on an illustrated embodiment.

First, before entering into a description of the configuration of the film information reading device for a camera according to the present invention, the film information hole 1 in the roll film 11 that is to be read by the device according to the present invention.
The formation mode of 1C will be explained. As shown in FIG. 3, this roll film 11 has a code information area A for 15 perforations llb along the upper edge of its tip, and each perforation in between 1it), a maximum of 14 film information holes 11c are formed between the holes 11c. This information hole
As can be seen from the table shown in Figure 4, the film information hole 11cI closest to the tip of C is an information hole for generating a start pulse, and must be used to instruct the reader to start reading the code. It is perforated. Further, the film information hole 11CI4 at the most proximal edge is an information hole for generating an end pulse, and is always punched. And the image information hole 11c
Information holes 11c2 to 11cI3 between perforation lb and 11cI4 represent film information such as film sensitivity and the number of frames that can be taken as code information.
The holes are selectively drilled in between depending on the code information.

FIG. 5 shows a film information reading device for a camera according to an embodiment of the present invention, which reads information from the roll film 11 shown in FIG. 3 above.

This film information reading device is disposed on the film winding side of the camera body 6, and includes a sprocket 7 that feeds the film 11 by writing a feed pawl 7a into the film IH7) perforation llb, and A light emitting element 8 disposed inside the sprocket 7 and a plurality of holes (
In this example, the light guide holes 7b (eight in this example) and the light led out from the light guide holes 7b are transferred to the film information holes 11 of the film 11.
A light-receiving element 9 for code reading disposed on the back cover 10 is engaged with the feed pawl 7a of the sprocket 7 so that light can be received through the light-receiving element 9. Its main part is composed of a sprocket rotation detection switch SW2 that generates a signal.

As shown in FIG. 6, the sprocket 7 is formed of a cylindrical body with a plurality of (eight in this example) feed pawls 7a protruding from the outer peripheral surface near the upper end and the lower end, respectively. The upper end is fitted into a bearing hole drilled in the camera body 6, and the lower end is fitted into a sprocket shaft 13 fixed to the camera body 6, so that it can rotate freely about the sprocket shaft 13. It is located in The sprocket shaft 13 is formed of a hollow shaft having a flange or the like for fixing the coaxial shaft 13 to the camera body 6 at its lower end, and a tip extending all the way to the upper end of the sprocket 7. , the light emitting element 8 is arranged at a height corresponding to the feed claw 7a. This light emitting element 8 is connected to a code detection circuit (see FIG. 9), which will be described later, through lead wires 14a and 14b inserted through the sprocket shaft 13. Further, a diaphragm member 15 made of a short cylindrical body is attached to this light emitting element 8 so as to surround the element 8, and the member 15 has a diaphragm member 15 that can face the light receiving element 9 for reading the code. The aperture hole 15a is located at the height and direction position.
(See Figure 5) is drilled. In addition, at the intermediate position between the feed pawls a on the upper side of the sprocket 7,
The light guide holes 71) are formed centripetally.

The light guide hole 7b is positioned at a height and direction such that it can correspond to the film information hole 11c of the film 11, which is fed by writing the feeding claw 7a in the perforation llb.

Further, a clutch member 16 for transmission is fixed to the upper end of the sprocket 7 so as to form an upper part of the camera body 6. One or more vertical seating grooves (not shown) are formed on the outer circumference of the upper end of the clutch member 16, and the rotating seating grooves have vertical seating grooves on the lower inner peripheral surface of the clutch member 17 for transmission. One or more protrusions (not shown) protruding from the surface are fitted. A sprocket drive gear 18 is fixed to the outer periphery of the transmission clutch member 17 in the middle thereof, and during film winding, rotational force is transmitted from a film winding lever (not shown) to the gear 18. This is transmitted to the sprocket 7 via the clutch members 17 and 16, and the sprocket 7 rotates once, and the take-up spool i9 (
(See Figure 5). The transmission clutch member 17 has an upper end fitted into a bearing hole drilled in the base plate 21 and is rotatably and slidably disposed between the member 17 and the base plate 21. The interposed extensible coil is biased downward by the clutch spring 22, and the protrusion latch member 16
It is connected to the same member 16 by being fitted into the slotted groove. However, when rewinding the film, the clutch member 17 is moved by known means (not shown) against the elasticity of the spring 22 to an upper position where it is not connected to the clutch member 16. When you do,
The clutch member 16 and the sprocket 7 are rotationally free, and the film 11 can be easily rewound.

On the other hand, as shown in FIG. 5, the code reading light receiving element 9 is located on the optical axis of the light beam passing through the aperture aperture 15a, the light guiding hole 7b and the film information hole 11C (see FIG. 7). The back cover 10 is supported by the supporting members 25 and 26 so as to
is attached to. The support member 25 is provided with an opening through which the light beam passes. The code reading light receiving element 9 is connected to a code detection circuit (see FIG. 9) disposed on the side of the camera body 6 through a line on a flexible printed circuit board 27 extending along the inner surface of the back cover 10. It is connected.

Further, the sprocket rotation detection switch SW2 is formed of two conductive contact pieces 12a and 12b whose base ends are fixed to the camera body 6 by a support member 28, and the tip end of one of the conductive contact pieces 12a is , extends so as to be able to engage with the feed pawl 7a of the sprocket 7. When this one conductive contact piece 12a is engaged with the feed pawl 7a, the other conductive contact piece 12b
When it comes into contact with the switch SW2 and closes the switch SW2, and is not engaged with the claw 7a, its own elasticity causes the other conductive contact piece 12 to close.
The switch SW2 is opened by moving away from the switch SW2. Therefore, the switch SW2 repeats opening and closing as many times as the number of feed pawls 7a, that is, eight times, as the sprocket 701 rotates to feed one frame of film 11. Further, the closing timing of this switch SW2 is adjusted so as to substantially coincide with the timing when the light guiding hole 7b faces the light receiving element 9. This switch SW2 is connected to a code detection circuit (see FIG. 9) by connecting both conductive contact pieces 12a and 12b to the code detection circuit (see FIG. 9) through lead wires 29a and 29b.

On the other hand, a reset switch 5Wo (see FIG. 9), which will be described later, is formed near the rear right corner of the camera body 6.
Conductive contact pieces 31a and 31b and a back cover opening/closing signal transmission member 32 are respectively provided.

The back cover opening/closing transmission member 32 has a base end fixed to one conductive contact piece 31a, and a distal end passing through a through hole provided in the camera body 6, and being guided by the through hole. The elasticity of the one conductive contact piece 31a urges the back cover to protrude toward the other side. When the back cover lO is closed, the transmission member 32 is pushed by the back cover lO and slides toward the inside of the body, and both conductive contact pieces 31a, 31
B is made conductive, and the reset switch SWo is turned on. Both the conductive contact pieces 31a and 31b are
Lead wire 33a.

33b, it is connected to a code detection circuit (see FIG. 9).

In FIG. 5, reference numeral 34 indicates a film pressure plate disposed on the inner surface of the back cover 10, and 35 indicates a leaf spring member for attaching the film pressure plate 34 to the back cover 10.

FIG. 8 shows an outline of the electric circuit of the film information reading device of the present invention. This electric circuit consists of the film 11
a code detection circuit 41 for reading out film information from the film information hole 11C; a decoder 42 for converting the film information read by the code detection circuit 41 into information for display or calculation; A selection signal 5EL is generated from the converted film sensitivity value Sv, the aperture value AvH manually input from the outside, the subject brightness value Bv, the shutter speed value Tv, and the correction value Cv.
An arithmetic circuit 43 that calculates an appropriate shutter speed value Tv or aperture value Av according to the ECT, a display circuit 44 that displays the shutter speed value Tv or aperture value Ay calculated by this calculation circuit 43, and the above code. a clock generation circuit 45 that supplies a clock pulse φ to the detection circuit 41 and the arithmetic circuit 43; and a film frame number counter 46 that subtracts the number of frames that can be photographed based on the outputs of the code detection circuit 41 and decoder 42. The main parts are a film frame number display section 47 that displays the number of frames counted by the film frame number counter 46, and a reset switch SW0 that resets the code detection circuit 41 and the frame number counter 46 to their initial states. It is configured.

FIG. 9 shows the code detection circuit 41 shown in FIG. 8 in more detail. In this code detection circuit 41, the symbol EPDo indicates a light emitting element 8 (see FIGS. 5 and 6) disposed within the sprocket 7, and the anode of this light emitting element gPDo is connected to a constant current circuit CC, is connected to an operating power source (not shown) through. Also,
The cathode of the light emitting element EPDo is grounded via the collector/emitter of a switching transistor Qo for light emission control.

This transistor Q. is formed of an NPN type transistor, and its base is connected to the output terminal of a NOR gate G, which will be described later, through a resistor R0.

Further, the code PD indicates the light receiving element 9 for reading the code (
(see FIG. 5), and the cathode of this light receiving element PD1 is connected to an operating power source through a load resistor R1. The anode of the light receiving element PD is grounded through the base and emitter of the transistor Q2. The transistor Q2 is of the NPN type, and forms a phototransistor together with the light receiving element PD, and its collector is connected to the operating power supply through the resistor R1.
It is also connected to the inverting input terminal of comparator A2. The comparator A2 is of the hysteresis type, and there is no comparator A2. A divided comparison voltage VT2 is generated at the connection point between these two resistors R,,,R,, and this comparison voltage V
T2 is applied to the non-inverting input of sparator A2.

The sprocket rotation detection switch SW2, which is made up of the two conductive contact pieces 12a and 12b (see FIG. 5), has one end connected to an operating power source, and the other end grounded through a discharge resistor R2. It is connected to the input end of buffer amplifier A1 via capacitor C1. Also,
The input end of this buffer amplifier A is grounded through a charging resistor R3.

The output terminal of the buffer amplifier A is connected to the JK-flip-flop circuit F (hereinafter referred to as the flip-flop circuit).
(abbreviated as P), the input terminal J1 of the inverter I
They are respectively connected to the input terminal K of the same FF through N1. Further, a clock pulse φ output from the clock generation circuit 45 (see FIG. 8) is applied to the clock signal input terminal CK of JK-FFF.
The reset signal input terminal R is connected to the reset signal RESET (
It is connected to the output terminal of the buffer amplifier A3 which outputs the signal in FIG. 11 (see at). The non-inverting output terminal Q of JK-FFF is connected to the input terminal J of the next stage JK-FF F2, and
The inverting output terminals Q are respectively connected to the input terminals K of JK-FF F2. A clock pulse φ is applied to the clock signal input terminal CK of JK-FF F2,
The reset signal input terminal R is connected to the output terminal of the buffer amplifier A3. This JK-F, F” F, , ,
F2 and the inverter IN form a known delay circuit, and a clock signal CL is used to set the reading timing of the information code output from the buffer amplifier A.
It serves to delay Ka (see FIG. 11 (arrow)) by about two periods of the clock pulse φ and output it as a clock signal CLKb (see FIG. 11 (see cl)).

JK-FF F2 that outputs the above clock signal CLKb
The non-inverting output Q of the four JK-FFFAs forming an up-counter UC for perforation counting
It is connected to the clock signal input terminal CK of the first-stage FFFAo of the o-FA3, and is also connected to the first input terminal of the three-person AND gate Gl.

It is also connected to a film frame number counter 46, which will be described in detail later in FIG. 10. The non-inverting output terminal Q of the first stage FFFAo is connected to the clock signal input terminal CK of the next stage FFFA, and in this way, the four J
K-FFFAo to FA3 are connected in cascade, with the non-inverting output terminal Q of the FF in the previous stage being sequentially connected to the clock signal input terminal CK of the FF in the succeeding stage.

Input terminals J and K of each JK-FF FAo-FA are connected to an operating power supply, and are connected to a reset signal input terminal RU and an output terminal of a buffer amplifier A, respectively. Non-inverting output terminal Q of final stage FF FA
is connected to one input terminal of AND gate G.

On the other hand, the output terminal of the comparator A2 is connected to the set signal input terminal S of the R, 5-FF Fo forming the latch circuit, and is also connected to the input terminal of the inverter IN. The reset signal input terminal R of R8-FF Fo is connected to the output terminal of OR gate G4, one input terminal of OR gate G4 is connected to the output terminal of buffer amplifier A3, and the other input terminal is connected to the output terminal of buffer amplifier A3 through inverter IN2. Same T
The non-inverting output terminals QIC1 of IL8-FF'o are connected to each other.The non-inverting output iQ of IL8-FF Po is connected to the other input terminal of the AND gate G3 through the inverter IJ'J. and gate G1
It is also connected to the second input terminal of. The output terminal of the AND gate AS is connected to a resistor through a buffer amplifier A5. One end of the resistor R is redundantly connected, and the other end of the resistor R is connected to the base of a switching transistor Q3 for light emission control. This transistor Q3 is formed of an NPN type transistor, and its collector is normally connected to the canard of a film-mounted light emitting element EPD for warning display, and its emitter is grounded. The anode of the light emitting element EPD is connected to an operating power source through a constant current circuit CC2. Further, the output terminal of the above-mentioned ant gate G3 is also connected to the other input terminal of the NOR gate G. One input terminal of the NOR gate G is connected to the output terminal of the three-person gate G2, and each input terminal of the AND gate G2 is
Of the four JK-F'F]';"Co-F'C forming the up counter tJc2 for counting the information hole, FF' is connected to each non-inverting output end of FC, ~Fc3. The above AND gate G2 opens the information hole when the up counter UC2 reaches ]4 count.
, ]C is a gate for outputting a reading stop signal 5TOP, and its output end is connected to a film frame number counter 46, which will be detailed later in FIG. , is also connected to the third input terminal of . Also, I:/Bata IN3
The output terminal of is also connected to a film frame number counter 46, and is adapted to supply the counter 46 with an inverted signal 'ij 5TOP (see FIG. 11 (gl)) of the stop signal 5TOP.

The output terminal of the AND gate G is connected to the clock signal input terminal CK of the JK-FF FCo of the first stage of the up counter TJC2 for counting information holes, and the 14 gates forming the shift register sR1 for storing codes. I
) JK-FF F'5o-FS, , are connected to each black signal input terminal cr<. The up counter Uc2 for counting the information hole is the first stage FFF.
The non-inverting output terminal Q of co is connected to the clock signal input terminal CK of the next stage FF PC, and in this way,
Four JK, -FF FCo-FC3 are connected in cascade, and the inputs mJ and K of each FF FCo-FC3 are respectively connected to an operating power source. Also,
The reset signal input terminal R of each FFFC8 to FC is connected to the output terminal of the buffer amplifier A3.

Furthermore, the outputs 14Q of the JK-FFs PC, .about.FC3 in the subsequent stages are respectively connected to each input terminal of the AND gate G2.

Further, the output terminal of the inverter IN6 is connected to the inverter I
JK-1;"F' FSo-F forming the shift register SR, with or without N7;
Of S and 3, the input terminals J and K of the first stage OFF' FSo are respectively connected. And the first stage FF
'FS.

The non-inverting output terminal Q and the inverting output iQ of
are connected to the input terminals J and K of FS, respectively,
Hereinafter, in this way, 14 JK-FF PSs.

~FS', , are cascaded to form a shift register SR.

is formed. Also, each pr P″5o−=FS,
The non-inverting output terminals Q of No. 3 are each connected to the decoder 42, and from the decoder 42, the decoded film sensitivity information and the photographable frame number information are sent to the arithmetic circuit 43 and the film frame number counter 46, respectively. is now being transmitted.

On the other hand, the reset switch SWo, which is made up of the two conductive contact pieces 31a and 31b and the back cover opening/closing signal transmission member 32 (see FIG. 5), has one end connected to the operating power source,
The other end is grounded through the discharge resistor R7, and
It is connected to the input end of buffer amplifier A3 via capacitor C6. Further, the input terminal of the buffer amplifier A30 is grounded through a charging resistor R8.

FIG. 10 shows the film frame number counter 46 shown in FIG. 8 in more detail. This film frame number counter 46 includes eight JK-FF FDo-FD7 and one
It is composed of a well-known presettable down counter formed by six Nando games) G and O-02g. The above 8 JK-FF' FDo-FDs are OFF in the front stage.
The non-inverting output terminal Q is the clock signal input terminal C of the latter stage OFF.
K[They are connected in sequence to form a down counter DC, and the clock signal input terminal CK of the first stage OFF FDo is the non-inverting terminal of JK-FF FB3, which becomes the output terminal of an up counter UC for frame advance detection, which will be described later. Connected to output terminal Q. Moreover, input terminals J and K of each JK-FF FD, -FD are connected to an operating power source, respectively.

On the other hand, one input terminal of each Nando game) G +o-025 is connected to the output terminal of the inverter IN5 (see FIG. 9), and an inverted signal 5TOP (of the stop signal 5TOP) is output from the inverter IN3. Figure 11 (g
)). Also, among the Nando games) G + o-025, half of the Nanto gates with odd subscripts G, , G, 8. ...,
The other input terminal of G2° is connected to each output terminal of the decoder 42, respectively. Furthermore, the other half of the Nant gates G, 0 . G, 2. ...,
The other input terminal of G2° is half of the Nando games with odd subscripts) G, , G, 3. . . . are respectively connected to the output terminals of G25. Then, half of the Nantes gates with even subscripts q+o * Gl□,...
, G2° output terminal is the above JK-FF F'Do-FD7
Half of the Nantes gates G B r GI3 with odd number subscripts are connected to each reset signal input terminal R of
+..., G2. The output terminal of JK-FF FD, -F
They are respectively connected to each set signal input terminal S of D7. Also, each FFFD.

~The non-inverting output terminal Q of the FD 7 is connected to each input terminal of a display decoder 48, and the output terminal of this display decoder 48 is connected to the film frame number display formed by a liquid crystal display board, a light emitting diode display element, etc. 47. In addition,
The display decoder 48 receives the stop signal 5TO.
P is input, and the same signal 5TOP is
When the H level is reached, the decoder 48 starts operating and the number of film frames is displayed on the display section 47.

The up counter UC3 for detecting the frame withdrawal feed counts the clock signal CLKb and outputs a frame number signal CLK every 8 counts, that is, every time one frame of the film 11 is fed.
It is for outputting d, and four JK-FIi
” FEo-FB are connected in cascade.

That is, the non-inverting output terminal Q of the previous stage OFF is sequentially connected to the clock signal input terminal CK of the subsequent stage FF, and the first stage P
I';' The clock signal input terminal CK of FEo is connected to the J
It is connected to the non-inverting output terminal Q of the K-FP F2, and receives the application of the clock signal CLKb (see FIG. 11(C)). Also, each JK-F to 1FEo-
The input terminals J and l of FE3 are connected to the operating power supply respectively.Furthermore, the reset signal input lR of each FF FE0 to FE is of course connected to the output terminal of FF G and 8. , one input terminal of the OR gate G18 is connected to the non-inverting output terminal Q of the TK-FF FB3, and the other input terminal is connected to the output terminal of the AND gate GI. A stop signal 5TOP is applied to one input end of the AND gate G19, and the stop signal 5TOP is also applied to one end of the resistor R8°. The other end of the resistor R,o is grounded via the capacitor C2, and is connected to the input end of the inverter IN, and the output end of the inverter IN is connected to the other input end of the AND gate G. It is connected. The above resistor R1o, 1:2 capacitor C2
, inverter IN, and AND gate G1. forms a circuit for generating a positive reset pulse at the rising edge of the stop signal 5TOP.

As described above, the camera film information reading device of the present invention is configured.

Next, we will explain the operation of this film information reading device in the first part.
Figures 1(a)-(il and Figure 12(al-tel)
This will be explained with reference to the time chart.

First, when the back cover 10 of the camera is opened and the film 11 is attached, and the back cover 10 is closed, the back cover opening/closing signal transmission member 32 is pushed by the back cover 10 and becomes a conductive contact. 31a and 31b are short-circuited, and the reset switch SWo in FIG. 9 is closed. Then, capacitor C8, resistor R
8, a positive pulse is applied to the input terminal of the buffer amplifier A3, which is waveform-shaped by the same amplifier A, and the first
A reset pulse RESET as shown in FIG. 1(a) is generated at the output terminal of the buffer amplifier As. This reset pulse RESET is applied to R8-FF forming a latch circuit.
Fo, JK-FF F forming a delay circuit, and F2
．． Up counter UC, and UC2'& form JK
-FF FAo-FA, FC6 to FC, and JK-FF FSo forming shift register SR
- PS, the reset signal of each FF' of 3 is applied to the human power end R, and the output of each FF is reset to l L level. Therefore, the output of up counter UC, and the output of up counter UC2 are all °L level, and the alarm signal ALARM, which is the output of AND gate q3, is l Ll level.
The stop signal 5TOP, which is the output of the AND gate G2, becomes the 'L' level (see Fig. 11 (g+)). Therefore, the output of the NOR gate G becomes the "Hl level", and the transistor Q. is turned on, and as shown in FIG. 11 (1), the light emitting element EPDo (
81 lights up. Then, in FIG. 5, the light emitting element 8
The light emitted from the (EPDo) passes through the aperture aperture 15a of the aperture member 15 to the light receiving element 9 for code reading (
PD, ), but in the initial state, if the aperture aperture 15a does not correspond to the light guiding hole 7b of the sprocket 7, the light is blocked by the sprocket 7 and passes through the light receiving element. 9, and the output C0DEa of the comparator A2 remains at the T I,l level, as shown in FIG. 11 (di).

Next, when the film 110 is wound up in order to empty the exposed portion at the leading edge of the film, in FIG.
The sprocket 7 rotates counterclockwise while sequentially inserting the feed pawl 7a into the (-foration llb) of the film 11, and the film take-up spool 19 rotates clockwise so that the film 11 is placed on the spool 19. It is wound up one after another.At this time, as the sprocket 7 rotates, one conductive contact piece 12a of the sprocket rotation detection switch SW2 and the sprocket rotate.

The feed claw 7a of the rocket 7 engages with the switch SW2.
is opened and closed intermittently. Therefore, )(sofa amplifier A,
A positive differential/< pulse is generated sequentially at the input end of the amplifier A, and this is waveform-shaped by the same amplifier A to generate a period corresponding to the winding speed of the film 11 as shown in FIG. 11 (bl). This clock signal CLKa is output as a clock signal CLKa having a
-FF A delay circuit consisting of F, , F2,
□The clock signal CLKb is delayed by about two periods of the lock pulse φ and output as the lock signal CLKb as shown in FIG. 11(c). This clock signal CLKb is applied to the up counter UC, and , are sequentially counted up, and are manually input to AND gate G1. However, in the early stage of film winding, R8-
Start signal 8TAFllT which is the output of F'F FO
Since is the degree L level (see tel in FIG. 11), output of the clock signal CLKc is not started from the controller [3] (see tel in FIG. 11).

On the other hand, as the sprocket 7 rotates and the film 11 is fed, as shown in FIG.
Of the film information holes 11C, the information hole 11c for generating a start pulse corresponds to this. This information hole 1
1C1 is fed in a state that is aligned with the light guide hole 7b of the sprocket 7, and the light guide hole 7b is aligned with the aperture aperture 15a.
Corresponding to this, the light emitted from the light emitting element 8 is transmitted through the aperture aperture 15a and the light guide hole 7b.

The light passes sequentially through the information hole 11C+ and enters the code reading light receiving element 9. Therefore, the photocurrent flowing through the light receiving element 9 (PD, ) increases, and in FIG. 9, the voltage applied to the inverting input terminal of the comparator A20 decreases, and the code signal C0DEa, which is the output of the comparator A2, becomes the first
As shown in FIG. 1(d), it is inverted to +H+ level. Then, at the first rise of this code signal C0DEa, R
8-FF' Fo is set, and as shown in FIG. 1(e), its output, the start signal 5TART, becomes lH.
Invert to l level. This start signal 5TART is
The start signal 5TAR is inverted through the inverter IN and applied to the reset signal input terminal R of the same FFFo.
T is latched at the 'H' level by R8-FF' Fo.Therefore, from now on, regardless of the change in the code signal C0DBa, the reset signal R is applied through the OR gate 6.
Unless ESET is applied to the reset signal input terminal R,
T(S-FF Fo does not change its state, and the start signal 5TART maintains the °H level. Also, the start signal 5TART is input to the AND gate G1, and the gate G is input to the second and third The input end becomes 'H level (
(see FIGS. 11(e) and (g)). Therefore, from then on, the output changes according to the level of the clock signal CLKb, and the 11th
As shown in Figure (f), a clock signal CLKc is output.

Furthermore, the start signal 5TART is applied to the inverter IN.

is inverted and applied to the other input terminal of the AND gate G, closing the AND gate G, and inverting the up counter UC,
Regardless of the output of , the output of AND gate G3 is °L
°Fix it so that it does not change from the level.

Therefore, from then on, transistor Q3 will no longer be able to turn on.
The warning display light emitting element EPD no longer lights up.

Then, when the sprocket 7 is further rotated, the aperture aperture 15a and the light guiding hole 7b no longer correspond to each other again, and the light is no longer incident on the code reading light receiving element 9.
The photocurrent flowing through J (PD, ) decreases. Therefore, the potential at the inverting input terminal of the comparator A2 rises again, and the code signal C0DEa, which is the output of the comparator A2, is again inverted to the l L l level, and the detection of the information hole 01 for generating the start pulse is completed. .

The sprocket 7 has an information hole 11 for generating a start pulse.
It continues to rotate even after the detection of C1 is completed, but along with this,
The information holes 11c2 to 11c+3 representing the information code or their non-perforated portions pass between the light emitting element 8 and the light receiving element 9 in correspondence with the light guide hole 7bK).

Therefore, the code information section A of the film 11 corresponds to the pixel 8°9.
After passing through all the steps, the output terminal of comparator A2 has a waveform as shown in FIG. 11(d) (however, in this case,
Code information for 14 pintos is '11101001300
011'. ) code signal C0DEa is obtained. This code signal C0DEa is applied to inverter IN6.
Through IN7 and inverter IN, JK-FFF
The bits are input to the input terminals J and K of the AND gate G1, and are sequentially taken into the shift register SR, while being shifted one bit at a time in synchronization with the clock signal CLKC applied to the AND gate G1 color shift register SR, and converted into a code. Stored as signal C0DEb (see FIG. 11(h))
.

In addition, the above 07 signal CLKc is the JK-FF ii
”c, code signal C0DEa which is also applied to the clock signal input terminal CK and taken into the shift register SR.
The up counter UC2 counts up the number of bits. And the same counter UC2
When the count number reaches 14 counts, that is, the number of information bits of the code information section A, the outputs of JK-FF PC, ~FC8 all become "H" level, and the stop signal S, which is the output of the AND gate G2, is activated. 'l' OP is inverted to 'H' level (see Figure 11(g)), Noah gate G,
As shown in FIG. 11(i), the output of the AND gate G1 is set to the Ll level, and the light emitting element EPDo (8) is turned off, and the third input terminal of the AND gate G1 is set to the IJ,L level through the inverter IN. Then, as shown in FIG. 11(f), the subsequent output of the clock signal CLKc is stopped.

In addition, the stop signal 5 output from the inverter N3
The inverted signal 5TOP of TOP (see Fig. 11(g)) is
It is also input to a film frame number counter 46 shown in FIG. This inverted signal S'rOP is at lHl level before the reading of the information code is completed, and in this state, the decoder 4
The outputs that have the same level as each level of the 8-bit film frame number signal output from 2 are output from each JK, -FF"
It is obtained at the non-inverting output terminal Q of FDo-PD7. That is, when the output bit of the decoder 42 is at the lHl level, the set signal input terminal S of the JK-FF is at the °L level,
When the reset signal input terminal R is at the °H" level, the output terminal Q is at the "H" level, and the output bit of the decoder 42 is at the "L" level, the set signal input terminal S of the JK-FF is at the "H" level. , the reset signal input terminal R is at the L level, and the output terminal Q is at the °L level.Then, from this state, as the information code is read, the inverted signal 5TOP is transferred to the I L l level. Then, JK-F
Since each set signal input terminal S and reset signal input IR of F'F'Do-F'D7 are all at the °l-1' level, the down counter DC, is the amplifier counter UC5.
At the rising edge of the frame feed signal CLKd output every 0.8 counts, the number of film frames held in the JK-FF FDo-PD7 can be sequentially counted down. The number of film frames held in the down counter DC is decoded by the display decoder 48, which starts operating in synchronization with the stop signal 5TOP inverted to °H level upon completion of reading the information code. and displayed on the film frame number display section 47.

Furthermore, upon completion of reading the information code, a stomp signal 5 is sent.
When TOP changes to “H” level, AND gate (3+
One input terminal of o becomes "H level, and the other input terminal becomes °L level after a moment delay due to resistor R1 (+), CR circuit of capacitor C2, and inverter IN.
ANDGATE G1. A reset pulse of °H level is generated at the output terminal of . This reset pulse is applied to JK-PFFE through OR gate G18.

~FE, is applied to each reset signal input terminal R, and is counted by an amplifier counter UC3 for frame advance detection. This reset is performed in order to start counting the first frame of the film 11 from the position where reading of the information code ends.

When the sprocket 7 rotates once and the film 11 is wound up by one frame after reading the information code, the up counter UC3 changes to the clock signal CL.
After counting Kb to 8, the non-inverting output terminal Q of JK-FFFE becomes "H" level. Then, the rising edge of this output is sent to JK-PF Ii”D as frame feed signal CLKd.
The down counter DC, counts down the number of film frames held by one. The counted down number of film frames is displayed on the film frame number display section 47 through the display decoder 48.
is displayed.

On the other hand, the output of JK-FF FE3, which has changed to l Hl level, is slightly delayed through OR gate G18 and
K-FFFEo-FE, are applied to each reset signal input terminal R. Therefore, the up counter UC3 is reset and the output of JK-FIi' FE3 is immediately
Return to L' level. Therefore, the frame feed signal CL K
d becomes a positive pulse-like signal.

In this manner, each time the film 11 is wound by one frame, one pulse of the frame advance signal CLKd is output, and the down counter DC counts down one by one. The counted down film frame number is displayed on the film frame number display section 47.

The film sensitivity value Sv read as film information together with the number of photographable frames is decoded by a decoder 42 and inputted to an arithmetic circuit 43 shown in FIG. The calculation circuit 43 calculates an appropriate shutter speed value Tv or aperture value Av from the film sensitivity value Sv, externally set aperture value Av or shutter speed value Tv, brightness value Bv, correction value Cv, etc. , this is displayed on the display circuit 44. In addition, when the camera is shooting, the appropriate shutter speed value T
v or the aperture value Ay is input to an exposure control circuit (not shown), and the exposure operation is controlled based on this.

The above is the operation of the film information reading device of the present invention when the roll film 11 having the film information hole 11c is loaded in the camera. When a roll film is loaded, the operation is as follows.

First, open the back cover 10 of the camera, load a roll film, and then close the back cover 10. When the back cover 10 is closed, the centrifuge switch SWo in FIG. )i, BSET is generated, and this reset signal RESET is R8-Fl" Fo, JK-F'F
'F.

F2. FAo-FA3. PCo-Fe2. FSo
~FS, 3 Reset each FF to @L level. Therefore, the output of the Noah gate q5 becomes "H level", and the light emitting element EPDo lights up as shown in FIG. Therefore, the light emitting element EPDo (8
) Even if the aperture aperture 15a and the light guide hole 7b match, the light emitted from the light receiving element PD for code reading, (9
) cannot be reached. Therefore, the film is wound up and the clock signal C is output as shown in FIG. 12(b).
Even if L K b occurs, the output of comparator A2 is T
I. Maintain the state of Rubel. Therefore, R8
-Start signal 5TART which is the output of FTi'Fo (
(see FIG. 11(e)) is also not inverted from the °L° level, and the AND gate G remains open.

Then, when the film is unwound by one frame and the count number of up counter UC reaches 8, JK-
The output terminal Q of FF' FA3 becomes "H level", and the output terminal of AND gate G becomes "L" as shown in Fig. 12 (C).
Warning signals ALA and RM at Hl level are output.

Therefore, the output terminal of the NOR gate G becomes the °L' level, and as shown in FIG. 12(d), the light emitting element EPD0
While the light is turned off, the transistor Q is turned on through the buffer amplifier AS1 and the resistor R11, and the light emitting element EPD for warning display is turned on. Therefore, the camera user receives a warning that the film 1 that does not have the film information hole 1tc has been loaded.

As described above, according to the present invention, the light emitting element is disposed inside the sprocket, and the film information hole is detected only by the light passing through the light guide hole of the sprocket. Even if the two forations are present together, the two can be reliably distinguished. Therefore, there is no possibility of misreading the film information.

In addition, the synchronization signal for reading film information is obtained not by optical means but by the opening/closing operation of a mechanical switch that detects the rotation of the sprocket. Exposure and fog can be prevented.

Furthermore, since the mechanical switch described above can be used not only for generating synchronizing signals but also for detecting frame advance, a separate frame advance detection mechanism is not required, and the IJX type camera equipped with a film information reading device can be used with Cost-effectiveness can be achieved.

Sara again, Noku-Folation, send nail? ”-a)
Since the film information hole is detected at a mechanically accurately positioned film part, even if the code information sound β is provided near the leading edge of the film, the film information cannot be detected reliably. Can be read.

In addition, if a film information hole is used, a warning display will be displayed when using regular film, so the user can manually set the film information based on this display. It is possible to prevent problems from occurring if you take an inappropriate photo.

Furthermore, since no aperture member is provided on the light emitting element, excessive exposure and fogging of the film can be effectively prevented.

Furthermore, since the light emitting element is turned off after the film information reading path is completed, unnecessary exposure and fogging of the film can be prevented. In particular, by doing so, the exposure caused by the detection light can be limited to only the unwinded portion of the film, so that fogging of the photographed image due to the detection light can be reliably prevented.

In addition, the light guide hole drilled in the sprocket has been made thinner, so
The configuration of the waveform shaping circuit for the photoelectric conversion output of the light receiving element can be simplified.

Therefore, it is possible to provide a film information reading device for a camera that is extremely convenient to use and eliminates the conventional drawbacks mentioned at the beginning of the specification.

[Brief explanation of the drawing]

FIGS. 1 and 2 are perspective views of main parts showing an example of a roll film having film information holes and a conventional detection mechanism thereof, respectively. FIG. FIG. 4 is a table showing the display contents of the code information section of the roll film shown in FIG. 3 above. FIG. 5 is a camera showing an embodiment of the present invention. FIG. 6 is an enlarged side view of the sprocket shown in FIG. 5, with the right hand section taken in section, and FIG. FIG. 8 is a block diagram showing an outline of the electric circuit of the film information reading device shown in FIG. 5, and FIG. , above No. 8
FIG. 10 is an electric circuit diagram showing the code detection circuit shown in the figure in more detail; FIG. 10 is an electric circuit diagram showing the film frame number counter shown in FIG. 8 in more detail; FIGS. (i
12 (al-( el is a time chart showing the waveforms of various signals in the film information reading device of the present invention when a normal roll film having no film information hole is loaded in the camera. 71... Sprocket 7a...・Feeding claw 7b...Light guide hole 5 (EPDo)...Light emitting element 9 (PD)...Light receiving element (film information hole detection means) 11 ・1.Roll film 11b... Exposure perforation SW2... Sprocket rotation detection switch 11C (I
ICI~11cI4)...-Flume Information Hole Outside 1
Figure b2 figure

Claims (1)

[Scope of Claim] A film information reading device for a camera that detects a film information hole punched in the film and reads film information such as film sensitivity and the number of frames that can be taken; a sprocket for writing and feeding the film; a light-emitting element disposed in the sprocket; a plurality of light guide holes centripetally formed at positions corresponding to the film information holes; film information hole detection means for receiving light guided from the light guide holes through the film information hole of the film; A sprocket rotation detection switch for generating an information read synchronization signal, which opens and closes according to the rotation of the sprocket corresponding to feeding one pass of the film, Camera film information reading device.