JPS5824123A - Film feeding method - Google Patents

Abstract

PURPOSE:To feed one frame portion exactly, by measuring a pulse generated at every unit shifting extent of a film, deriving a moving extent and a moving speed 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 shaped 20 for its waveform and is inputted to an MC40. 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, a timer incorporated in the MC40 is started, and a pulse interval T in case of a constant speed is measured. From the interval T, an overrun forecasting extent D is derived by use of an overrun extent correspondence table, and the remaining number C of pulses before driving of the motor 51 is stopped is calculated in accordance with the expression C=A-B-D-1. In this regard, the number A is the number of pulses required for the moving extent of 1 frame portion and is stored in advance. In this way, a film can be fed without being subjected to such influence as a fluctuation of battery voltage, irregularities of the film, a variation of ambient temperatures, etc.

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 automatic winder mechanism.

Various types of cameras (equipped with auto-winder mechanisms) have been known in the past, but the film
Frame feeding is turned on and off each time the film is wound up.
The film feeding motor was controlled by the F switch. For this reason, the amount of film fed is not constant and the film frame spacing varies due to the influence of changes in the output pressure of the battery (It source), variations in the film, and changes in the motor load due to changes in the ambient temperature. There were drawbacks.

The present invention has been made in view of this point, and includes a film feeding method in which a film feeding motor is controlled using pulses generated for each unit movement of the film to feed the film, and the pulses are measured. By the film feeding method, the amount of film movement and the film movement speed are determined, and the drive stop timing of the film feeding motor is controlled based on the movement mt and the movement speed. The present invention has realized a film feeding method that can always feed the film at a constant rate per frame without being influenced by various factors.

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, where io is a pulse generator. is a waveform shaping circuit, 30 is a switching circuit, aotI'i, one-chip microcomputer (hereinafter abbreviated as Me), ! O is a motor drive circuit, and 10 is a battery.

The pulse generator 10 outputs a pulse signal for each single movement distance of the film when winding the film.
Consists of a Siemens star-shaped slit disk (hereinafter referred to as Siemens star) that rotates in conjunction with film feeding, and LEDs and photodiodes 57 and 13 that are arranged facing each other with Siemens stars in between. has been done. Siemens Star/l has a large number of radially equal pitched slits/
La is provided with a nine circular plate, and by rotating this,
The beam irradiated from LID/λ to phototransistor/J is interrupted. Furthermore, I.J.D.
/λ and phototransistor /J each have a resistor /
The output voltage of the battery 10 is applied via λm, /Ja.

The specific mechanical part that rotates the Siemens Star l/ is as follows:
It is constructed as shown in FIG.

In other words, there is a reduction gear train on the output shaft of the film feed motor J/! -, the film 102 is fed by the rotation of the reel j3, and the sprocket lO/ is rotated in accordance with the feeding of the 10 films, and the rotation is reflected by a speed increasing gear train. Gear 10.3 → 104A410
! 410 to rotate the Siemens star // integrated with the gear lQt. Note that /j is a fixed Siemens star disposed coaxially with Siemens star //. With the above configuration, a pulse signal is outputted from the seven automatic transistors 3 for each unit movement amount of the film 10λ.

The waveform shaping circuit 20 is, for example, a Schmitt trigger circuit, and shapes the pulse signal applied from the phototransistor J into a pulse signal suitable for the MC4AO. This circuit controls ON/OFF of the power supply to the dipulse generator io, the waveform shaping circuit, and 20 by the control signals from the switching circuit JOi; There is.

A battery t is connected to this transistor TR.

An output voltage V is applied, and an eight-layer resistor is connected between the base and emitter. Furthermore, the pace is the resistance R,
When the signal is LOW, the transistor TR is turned on, and conversely, when the signal is HIGH, the transistor TRFiOνF
becomes.

The MC4IO executes a predetermined program, reads pulse signals, and controls each part.The MC4IO executes a predetermined program, reads pulse signals, and controls each part.
, a central processing unit (hereinafter referred to as CPU) 44 which is the center of control, an X10 port for data and control input/output, and a clock oscillator aS which supplies clock pulses for the CPU 7. There is. In addition, CPU$/ is connected to IOM≠2, via bus≠1,
The I10 port) $$, which exchanges data and control signals between the RAM $j and the X10 port H→, usually
Registers that temporarily store information, so-called latches,
It is composed of a decoder for addressing and selecting input/output circuits, and consists of a pressure input port and an output port. Input boat! ! The output signal of the waveform shaping circuit 20 is introduced into the output port 01, which sends a control signal to the switching circuit 30, and the output port 01 sends a control signal to the switching circuit 30. is a motor drive circuit! Sends a control signal to 0.

A motor drive circuit j0 drives a film feeding motor j, and the current flowing through the motor j/Kff is switched on and off by a transfer switch j3 of a relay j. Switch j3 is the renoid of relay j2! 0N due to external force
- When the OFF control is terminated and the switch j3 is turned OFF, the motor current is cut off and the film feeding motor j/ is braked.

Here, an example of the relationship between the amount of film movement and the speed is shown by the curved island in FIG. That is, when the film feed motor j/ is energized, the movement speed increases and the movement amount is 8. reaches a certain speed [Va. After that, even if the drive of the film feed motor J/ is stopped at the movement amount S&, the film feed motor ! Due to the overrun of l, it stops at a displacement a of 8e. This amount of overrun is approximately proportional to the speed Vl at constant speed. The curve in FIG. 3 is a characteristic curve when the battery is exhausted and the ambient temperature is lowered, and the amount of movement S until reaching constant speed and the speed vb at constant speed are different from curve a. Therefore, for example, in order to set the film movement amount to 8a, it is necessary to stop driving the film feeding motor jl at a movement amount of 8b, which is different from the case of the curved turtle. Characteristics also change due to film variations in the same way as described above. However, in either case, the overrun amount has a constant relationship with the speed (va, vb) at constant speed. Therefore, M
C4cO stores information about the film feed speed and overrun amount for cameras equipped with MCII.

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 ends, first.

MC 〇 is the predetermined number of pulses B that are generated until the movement speed of the accumulator ^q and 6 of the CPU 7 becomes sufficiently constant (for example, the pulses until the movement amount reaches 11k in Figure @ 3). (prestored in ROM≠λ). Next, output capo) LOW from Ox
Send a signal to energize the renoid j≠, and switch j
Turn on 3 and start the film feed motor j/. As a result, the film starts to move by 10λ, a pulse signal is generated from the pulse generator l111O, and a pulse signal is transmitted via the waveform shaping circuit 20 to the output signal of MC≠0. A lot of information is input. MCuO detects the rising edge of this pulse, and the contents (Aea) of accumulator Acc! , 91 is subtracted. After this subtraction, it is checked whether the no-rus count number has become B, that is, whether (AC-) has become 0,
If it is 1 or more, the pulses that arrive again are counted. (
People a@)”.

When this happens, the built-in timer is started, and the timer is stopped when the rising edge of the next pulse is detected.

As a result, the distance at constant speed is
(equivalent to the reciprocal of Va and Vb). From the T value of
Calculate the remaining number of pulses C until the driving of
Stored in OM#J l: Correction value for uncounted l pulses during pulse Sekisumi T measurement This value C is loaded into the accumulator Ace, and then subtracted (mus) every time a pulse is detected. If you do this, @ (hoe) = 0, it is difficult to judge whether it is true or not.
a)" (Continue counting until it reaches 7.
e) When it reaches 70, output a HIGH signal from the output boat 0, turn switch j3 to OFI, and stop driving film feed motor xi. As a result, film feed motor jl will overrun due to inertial force. , come to a complete stop. With this complete stop of the film feeding motor j/, the film lOJ is stopped. The deviation of the stopping position of the film lOλ from the normal stopping position is equal to the deviation of the actual O7(-run predicted weighing scale) from the actual OI(-run amount. The above discrepancy is extremely small because it was determined from the film feed speed/overrun amount vs. stone surface (before this correspondence was determined experimentally) in the camera.
λ stops in a nearly normal state.

In the above embodiment, the period of the output pulse of the Norculus generator 10 is sufficiently large compared to the period of the clock Norculus of the MCuO.・If it is not sufficiently large compared to the pulse period.

By attaching a counter externally or internally to the MC4fiO (the output of the pulse generator alLlo) and dividing the frequency appropriately, the obtained nine (
The film feed can also be controlled using the pulse.

Also, the first frame of photography is set by feeding 3 frames worth of film (blank feed), but the oat (-run amount) at the time of feeding these 3 frames is determined in advance by MC4cO
Store it in and use it. Alternatively, feeding control may be performed using 3m instead of A in the calculation formula for C. As explained above, according to the method of the present invention, battery voltage fluctuations, variations in various films, and surroundings can be controlled. It is possible to feed one frame of film without being affected by changes in motor load due to temperature changes.

Therefore, the piece spacing is always constant.

[Brief explanation of the drawing]

Fig. 47 is an explanatory diagram showing an embodiment of the film feeding method of the present invention, Fig. 1 is a schematic diagram of a part of the Siemens star, jl
Figure 3 is a characteristic diagram showing the relationship between film movement amount and speed.
The diagram is a flowchart for explaining the operation. 10...Pulse generator 410...Microcomputer jO...Motor drive circuit jl...Film feeding motor Patent applicant Roku Konishi Photo Industry Co., Ltd. Agent 9PI! Toji Shiijima

Claims (1)

[Claims] In a film feeding method that controls a film feeding motor and feeds the film using pulses generated for each unit movement of the film, by measuring the pulses,
A film feeding method comprising: determining a film movement amount and a film movement speed, and controlling drive stop timing of the film feeding motor based on the movement amount and film movement speed.