JPS5824125A - Film feeding method - Google Patents

Abstract

PURPOSE:To always make a frame interval constant, by receiving a pulse generated at every unit moving extent of a film, specifying an overrun extent of the film, and controlling the drive and stop of a film feed motor, in a camera provided with an auto winder. CONSTITUTION:A pulse generating device 10 outputs a pulse signal at every unit moving extent of a film when winding the film, and it is applied to an MC40. At first, to a CPU41 of the MC40, a prescribed number B of pulses generated before a film moving speed becomes a constant speed sufficiently is loaded. Subsequently, a feed motor 51 is started, and a pulse interval T in case of a constant speed is measured. After that, the remaining number C of pulses before driving of the motor 51 is stopped is calculated in accordance with the expression C=A-B-k/T-1. In this regard, the number A is the number of pulses required for the movement of 1 frame portion. Also, a constant (k) is proportion constant for deriving an overrun constant from a reciprocal of the pulse interval T. In this way, a film can be fed exactly without being subjected to such influence as a fluctuation of battery voltage, irregularities of the film and a variation of ambient temperatures.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film feeding method for accurately feeding one frame of film in a camera equipped with an autowinder mechanism.

Various cameras 2 equipped with an autowinder mechanism have been known in the past, but in this conventional camera, the feeding of the film frame is turned on and off each time the film is wound one frame.
The film feed motor was controlled by a switch. This has the disadvantage that the amount of film fed is not constant and the film frame spacing varies due to changes in the output voltage of the battery (power supply), variations in the film, variations in motor load due to changes in ambient temperature, etc. .

The present invention has been made in view of this point, and the film movement speed is determined by receiving a pulse generated for each unit movement of the film, and from this movement speed, the amount of film overrun after the drive of the film feeding motor is stopped. In a film feeding method in which this overrun amount is used as a factor for setting the driving stop timing of the film feeding motor, the overrun amount tk/T (where k is a constant and T is a pulse interval (time ) according to the film feeding method in which the following is the number of hours.

This method realizes a film feeding method that can always feed the film at a constant rate per frame without being affected by battery voltage fluctuations, film variations, ambient temperature changes, etc.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the method of the present invention, in which 10 is a pulse generator, 0 is a waveform shaping circuit, 30 is a switching circuit, 〇 is a one-chip microcomputer (hereinafter abbreviated as MC), 10 is a motor drive circuit, and to is a battery.

The pulse generator 10 outputs a pulse signal for each unit movement of the film during film winding. )// and 9 LID// placed opposite to each other with Siemens Star// in between.
λ and a phototransistor /J.

The Siemenster/l is a disk equipped with a large number of radially spaced slins) //a, and as it rotates, the beam irradiated from the IJD/- to the 7ototransistor/3 is now intermittent. Note that the output voltage of the battery 60 is applied to the LICD/co and the phototransistor 13 via resistors lc and /Jm, respectively.

The mechanical part that specifically rotates Siemens Star II is
It is constructed as shown in Figure 1.

Immediately, reel! is connected to the output shaft of the film feed motor j via a reduction gear train j 3 is delayed, this reel! The film 10λ is fed by the rotation of 3, and the sprocket 10/ is rotated due to the feeding of the 10 films, and the rotation is transferred to the gear 103 → 10 → 1os that forms the speed increasing gear train.
-Transfers to *iot and rotates -Siemen Star// which is integrated with car iot. In addition, /j is a fixed Siemens star arranged coaxially with the Siemens star - The negative waveform shaping circuit 20 is, for example, a Schmitt trigger circuit, and shapes the pulse signal given from the phototransistor /J into a pulse signal suitable for MCCo1.The switching circuit 30 is controlled by the MC4AO. It controls ON/OFF of the power supplied to the pulse generator IO and waveform shaping circuit -〇 by a signal, and is composed of a transistor R and a resistor ``1 + H2.'' The emitter of this transistor 'r11 is connected to a battery 60. An output voltage V is applied, and a resistor B1 is connected between the base and the emitter.Furthermore, the base is connected to MCu through a resistor.
When the signal is LOW, the transistor TR is ON, and conversely, the signal is HIGH.
When the level is H, the transistor TB is turned off.

MCCo1 executes a predetermined program and reads pulse signals*n to control each part, stores programs and stores data, and central processing unit (Central Processing Unit), which is the center of control. CPU below
) I1 for input/output of 44 data and control
It consists of a clock oscillator Hiromi that supplies clock pulses for the CPU 4'/0 port reference 1 and the CPU 4'. Furthermore, C.P.
U reference/ is connected to ROM41, RAM≠3 via bus reference
as well as! Data and control signals are exchanged with the 10 port 81. ! A 10-board board normally consists of an input port and an output port, each consisting of a register (so-called latch) for temporarily storing information, and a decoder for address selection of input/output circuits. human capo) It
The output signal of the waveform shaping circuit O is introduced into the output port.
) Send a control signal to the O1u switching circuit 30,
Also, output boat 02 is a motor drive circuit! Sends a control signal to 0.

The motor drive circuit 10 is a film feeding motor! The one that drives I relays the current flowing to motor J/K@! It is switched on and off by the transfer switch j3. Switch j3 is a relay! −'s Renoid! jQON
- When the switch j3 is turned off, the motor tg is turned off and the film feeding motor j/ is braked.

Here, an example of the relationship between film movement amount and speed is shown by curve a in FIG. 3. That is, when the film feeding motor j/ is energized, the moving speed increases and reaches a constant speed wjLVa at a moving amount 81. Then the amount of movement 8a
Even if the drive of the film feed motor j/ is stopped at
Stop at . This overrun amount is the speed 1 [V
It is approximately proportional to a. The curved line in FIG. 3 is a characteristic curve when the battery is exhausted or the ambient temperature drops, and the amount of movement until reaching constant speed and the speed *vb at constant speed are different from those of the curved island. Therefore, for example, in order to make the film movement amount S., it is necessary to stop driving the film feeding motor zi at a movement amount sb that is different from that in the case of one curve a. Characteristics also change due to film variations in the same way as described above. However, in either case, the amount of overrun is approximately proportional to the speed FIL (v&, vb) at constant speed.

Next, the operation of the apparatus configured as above will be explained with reference to the flowchart shown in FIG. This operation starts after the shooting is completed, and first, MC 〇 is a predetermined number of pulses B (for example, in Fig. With the number of pulses until the travel amount reaches 8k, load the (pre-stored in ROM≠λ).
The LOW signal is sent from Ox to energize the renoid j≠, and the switch j3 is turned on to start the film feeding motor jl. As a result, the movement of the film 102 starts and a pulse signal is sent from the pulse generator 10. occurs,
It is manually powered via the waveform shaping circuit 20 to the human powered boat It where MC≠O. MC San〇 detects the rising edge of this pulse,
Subtract l from the contents (Aea) of accumulator Aea. After this subtraction, whether the pulse count number has become B, that is, whether (A,,) has become O or not, is f"yl(
,, /″′″, ill, -7"6meri*u-"
Count the pulses that arrive. When (MUe@) = 0, start a software timer, detect the rising edge of the next pulse, and stop the timer. This measures the pulse interval ior, which corresponds to the reciprocal of vb at constant speed. Subsequently, the number C of remaining pulses until the drive of the motor is stopped is calculated based on the following formula.

C=mu B −k/T −/ ・・・・・・(1)
However, the number of pulses required to move one frame is
It is stored in advance in 4A.

The number of pulses corresponding to the amount of k/yH overrun, in addition,
This is a proportionality constant for determining the amount of overrun from the reciprocal of the pulse interval T, and is stored in advance in the MC reference Ovc.

l; Correction value for uncounted l pulses when measuring pulse interval T. This value C is loaded into the accumulator ■, and then subtraction (A@a) - / is performed every time a pulse is detected. I have to judge whether A...)=0 or not.
Continue pulse counting until .

(Mu**) When it becomes -O, the output port is 0! Than! 1IGH
Output the signal, turn off the switch j3, and turn the film feeding motor! Stop driving l. This allows the film feed motor! After l is operated by inertial force,
Stop completely. This film feeding motor! With the complete stop of l, the film 102 also stops. The deviation of the stop position of the film ioλ from the normal stop position is equal to the deviation of the predicted overrun amount /T from the actual overrun amount. By the way, since the actual overrun amount is approximately proportional to the speed at constant speed as described above, the above-mentioned deviation is extremely small, that is, the film lOλ stops in an approximately normal state.

In the above embodiment, the timer is configured with seven pieces of software, but a hardware timer may also be used.Also, the period of the output pulse of the pulse generator IO may be the period of the clock pulse of MC4!0. The configuration shown is for a case where the period of the output pulse is sufficiently large compared to the period of the clock pulse, but if the period of the output pulse is not sufficiently large compared to the period of the small clock/nox pulse, it is necessary to attach a counter externally or internally to the MC. Luz occurrence *
It is also possible to control film feeding by appropriately frequency-dividing the 1 to 10 output pulses and using the desired pulses.

As explained above, according to the method of the present invention, one frame of film can be fed without being affected by battery voltage fluctuations, variations in various films, motor load fluctuations due to ambient temperature changes, etc. .

Therefore, the piece spacing is always constant.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the film feeding method of the present invention, FIG. 2 is a schematic diagram of a part of the Siemens star, and FIG.
The figure is a characteristic diagram showing the relationship between the amount of film movement and the speed, and the second figure is a diagram of a fume chart for explaining the operation. 10... Pulse generator po -... Microcomputer! O...Motor drive circuit j/...Film feeding motor Patent applicant Toji Ijima, Roku Konishi Photo Industry Co., Ltd. Agent

Claims (1)

[Claims] The moving speed of the film is determined by receiving a pulse generated for each unit moving distance of the film, and the amount of film overrun after the drive of the film feed motor is stopped is determined from the moving speed, and the amount of overrun is calculated. A film feeding method in which the overrun amount is set as a factor for setting the drive stop timing of the film feeding motor, and the overrun amount is defined as % mold. However, k is a constant and T is a pulse interval (time).