JPS5821724A - Camera provided with electrical film counter - Google Patents

Abstract

PURPOSE:To reduce electric power consumption with respect to a camera wherein various parts are controlled by a microcomputer (MCU) and the number of wound frames of films is counted and displayed electrically by allowing the MCU to assume a stand-by mode and to stop electric power supply to peripheral circuits while the camera is not in use. CONSTITUTION:Since an end switch 13 is closed upon ending of a series of photographing sequence, an MCU10 goes to a stand-by mode, thus assuming the state of consuming electric power slightly. At the same time, the transistor TR of a stand-by circuit 11 goes off to stop supplying electric power to peripheral circuits ARC. As a result, the rate of the electric power consumption in said state is made slight and the data of the number of wound frames of the film, etc. during the period of the stand-by mode are stored in the RAM in the CPU10 without breakdown. Thus the electric power consumption of the camera while the camera is not in use is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera equipped with an electric film counter, and more specifically, a camera equipped with a microcomputer,
The present invention relates to a camera that controls the photographing distance and output, and electrically displays the number of frames to be wound on the film.

Recent cameras have become increasingly ``hidden'' and have become built into a control IC to automatically control each camera element. Furthermore, this control IC is progressing toward a dedicated L8x or a microcomputer. A microcomputer is a general-purpose IC that can be rolled up and used as a control IC to reduce costs. Furthermore, using a microcomputer has the advantage that the system can be easily changed by changing the software, and if the software is developed in-house, secretarial maintenance can be ensured. From these points of view, camera control using a microphone-like computer is currently attracting the most attention. By the way, the camera is equipped with a film counter that displays the number of stitches to be taken when winding the film, but conventional cameras still use mechanical film counters with a complicated structure. This is an obstacle to making cameras smaller and lighter. The reason electrical film counters are not used despite these obstacles is that they are expensive to keep the number of frames wound at the same time, and even when the camera is not in use, the power is turned on at 1k. Must be kept clean,
This is because the power consumed during that time will cause the battery to become exhausted. In other words, even if you use a low power consumption type C-MO8 microcomputer, the battery will run out due to the microcomputer's power consumption over a long period of time, resulting in the camera not working during actual use. I failed.

The present invention addresses the above points! This was done after the microcomputer went into standby mode and performed various controls in the evening and was not in sidelight or in the process of executing a shooting sequence, and then put the microcomputer into standby mode. By reducing the power consumption during non-photographing by stopping the power supply to the net-side circuit and minimizing the power consumption during non-photographing, a camera equipped with an electric film counter can be used without the problem of waste power. The present invention will be described in detail with reference to the drawings below.Figure 4: A built-in twinter controlled by a microcontroller according to the invention.
FIG. 2 is a diagram illustrating a main part configuration of an embodiment of an I camera with a shutter speed of K11l.

In the figure, l is a photometric circuit, C is a setting circuit, and 3□ is a tenalog calculation circuit. The photometric circuit 1 logarithmically transforms and amplifies the charging current of the external photometric photoelectric element /a to facilitate post-processing, and outputs the obtained luminance information P of the subject. The setting circuit consists of a sliding resistance for open F value vR1 which is set by attaching the photographic lens, a sliding resistance for film sensitivity vR1 which is set by the A8A dial,
The shutter second time set by the shutter dial is composed of the sliding resistance VR,
l vRm l VRI u, dividing the reference voltage vr, sliding resistance VR, one release r value information F.

, the sliding resistance VR, and the film sensitivity information 8.

The sliding resistor VR converts the shutter time information T into a Kameide decoding code and outputs it. The analog calculation circuit 3 is
The appropriate aperture value F is determined based on the luminance information P, the aperture F value information Fo, the film shock information S, and the shutter time information T. The appropriate aperture value information F output by 1NI3 and the shutter time information T obtained from the sliding resistance vB are alternately selected, and the analog-to-digital converter (
(hereinafter referred to as AD converter)! It is given to

B is a pulse generator for controlling the aperture, 7 is a pulse generator for braking the film counter, and the pulse generator for controlling the aperture 9 of the former is A4.
The aperture decreases as the lens narrows down! The latter film counter control pulse generator 7 generates pulses related to the film feeding amount as the film is fed. 7 has a similar structure, such as example f, which has a structure in which the light of the 7 Oto coupler is interrupted by a slit plate that rotates slowly in the aperture ring and sprocket. t is a drive circuit, ri is a display circuit, io
is a control microcontroller (hereinafter referred to as MCU)
It is. The drive circuit 5llt is used to excite and aperture each cylindrical magnet, drive the mirror and printer, and drive the film feed motor and charge motor based on commands from the MCU #. The display circuit also includes an electric film counter display circuit that displays the number of film winding frames on an LCD installed above the camera, and an exposure counter display circuit that displays exposure information (T and F) in the finer. Consists of an information display circuit.

MCUlo receives various signals such as the output signal of the AD converter j and the pulse generator 6. ．． It receives the output signals of 7, etc., and sends and controls the necessary signals to each part based on the pre-installed program.The central processing unit (ROM) that stores the program, and the RAM that stores the data (the central processing unit) It consists of a CPU), 110 ports for outputting data and control signals, and a clock oscillator that supplies clock pulses for the CPU. In addition, as MCUlo, low power consumption type C-MO
Preferably, an S one-chip microcomputer is used. This MCUlo is in standby mode, that is, the power is on but the clock oscillator is stopped and the MCU
2, which can enter a state in which the operation of the MC is temporarily stopped, and has a standby terminal.
U#) is a friend Vp hold terminal (I/.

boat) t-has.

ll is the standby circuit, /ko is the release switch, /3
is the photographing sequence end switch, / reference is the measurement and light switch, and lj is the battery. Standby circuit/, 1 is %MCU
This controls the power supply to the 10 peripheral circuits ABC.
A PNP switching transistor TR whose emitter is connected to the battery /J,) a resistor R1+ connected to the pace/transistor emitter of the transistor TH, and a transistor TH
It consists of a resistor R1 connected between the base of the 1141J original switch lv. This standby circuit// resistor R1 and the photometric switch/, the common connection black is the MCU
, are connected to the standby terminal of IO and the Vp hold terminal. Both the release switch saw and side light switching are opened and closed by the release button. That is,
The metering switch is on the 7th stage of the release button that is part of the switch mechanism! The first step is closed, and the release switch saw is closed at the second step. This release switch saw is compatible with MCUlo's I10 boat and Como.
connected between the lines. Also, photometry switch/4
'11114 is connected to the common line. The shooting sequence end switch IJ is a switch that closes during the shooting sequence and opens after the shooting sequence is completed. 10
Connected between boat and common line. The operation of the embodiment of the present invention with such a configuration will be described below.First, when the release button is pressed to the first step, the photometry switch l- is closed.

The human input signal to the standby terminal of MCUlo is 1Lm to f.
tt), MCUlo's standby mode is released.

On the other hand, the transistor TR of the standby circuit // is turned on when the photometric switch l≠ is closed, and the supply of power from the peripheral circuit RC4C battery starts.

As a result, the luminance information P of the object is outputted to the analog calculation circuit 3 from the photometry circuit that started the #1 light operation. Further, from the setting circuit 3, lens aperture f-number information Fo, film sensitivity information S, and shutter time information T are output to the analog calculation circuit 3. In the analog calculation circuit 3, appropriate aperture value information F is obtained, and this information F and the shutter time information T are combined with the analog switch circuit and the MU D converter! The data is read and stored in the MCU'10 via the MCU'10.

MCUloFi drives the display circuit to display this read information in the viewfinder. In case of overexposure or underexposure, a warning to that effect will be displayed in the viewfinder.・This is the preparation stage for shooting.

If you press the release button y further to the C position, the release switch will be closed and the MCU/0 connected to it will be closed.
A 1L'' signal is given to the Ilo boat of , MC.
Ulo is number 1 in this 'L11! When l-takes in, Vp
The L1 signal is output from the hold terminal and the following shooting sequence begins.The aperture ring is driven by the drive circuit l, the aperture ring is kept in a rotatable state, and the mirror is rotated. As the aperture ring is raised, the rotation of the aperture ring is started.This rotation of the aperture ring narrows down the lens, and the aperture control pulse generator 4 outputs a pulse signal to the MCUlo.The MCUlo emits this pulse, The counted value (corresponding to the amount of aperture reduction) is the appropriate aperture value information F stored earlier.
When the amount of aperture matches the aperture amount, the drive circuit stops energizing the aperture magnet and locks the aperture ring. Next, MCUlo causes the drive circuit to drive the front curtain magnet and move the shutter front curtain. Thereafter, when the time specified by the already stored shutter time information T has elapsed, the trailing curtain magnet is driven to cause the shutter trailing curtain to run.

After photographing, the MCU #) drives the charge motor by the drive circuit t to charge the aperture, mirror, shutter, etc., and then drives the film feeding motor. When the film feeding motor operates, the pulse generator 7 for controlling the film counter generates pulses corresponding to the amount of film movement.The MCUIO counts these pulses and when the provisional number of pulses is reached, that is, pulses for one frame of film are generated. After counting, the drive circuit 1 is controlled to stop the film feeding motor, the number of film winding frames is incremented, and the number of film winding frames is displayed on the display circuit. When the back cover of the camera is pressed, the number of film winding frames in the MCUIO is reset to a fixed value by interrupt processing, etc.).

When a series of shooting sequences are completed, the sequence end switch 13 is closed, so the MCU# connected to it is closed.
) signal given to the 110 boat becomes @L''.M
When CUIO takes in this @L" signal, it sets the vp hold signal to °■". At this point, the release button has returned to its open state before being suppressed, so the 6113 original switch/da is open. Afterwards, the MCU #) goes into standby mode9, resulting in a small power consumption state. At the same time, the transistor T of the standby circuit ll is turned off.
The F state rises, the power supply to the peripheral circuit mc is stopped, and the power consumption in the peripheral circuit mRC becomes zero. Note that during Jujlla in standby mode, data such as the number of film winding frames is stored in the RAM in the normal KMCU/7, so it will not be recorded. In this way, − times of photographing are completed.

To move on to the next shot, just press the release button in exactly the same way as in the case described above. , the above theory is that the release button is 1
This is about a camera with a step switch mechanism, and a shutter speed priority type camera with an internal winder. i#4ri can be used for 4 ways with cameras other than this type. Immediately after the side light switch 14I is set to - and the photographing sequence end switch 13 is closed, the power supply to the peripheral circuit RC is stopped.
(Number 9 indicates that the MCU/47 is placed on standby mode, but the state may be changed to the above state after a certain period of time has elapsed.

As explained above, in the present invention, after transitioning to a state where photometry is not in progress or a shooting sequence is not in progress, M
This allows the CU to go into standby mode and stops power supply to the peripheral circuits.The amount of power consumed in this state can be minimized. A camera that can electrically count and display the number of frames can be realized without causing problems with power consumption.

[Brief explanation of the drawing]

The figure is a structural diagram showing an embodiment of a camera equipped with an electric film counter according to the present invention. l...Photometering circuit λ...e & foot circuit 3...
・Analog calculation circuit Hiroshi...Analog switch circuit!
...AD converter t...Aperture lII control pulse generator 7...Film counter control pulse generator l...Drive circuit
ta...display circuit 10...V (croco/vieta/
/...Standby circuit l...Release switch/J...Photographing sequence end switch l-...Photometering switch /1...Battery A wing C...Peripheral circuit Patent applicant Kohyuroku Photo Works Osamu Ijima Co., Ltd.

Claims (1)

[Claims] It is equipped with a microcomputer that can take a standby mode, and controls the photographing sequence and exposure using the microcomputer, and when it is not in the process of metering or in the process of executing a photographing sequence, the microcomputer is not put into the standby mode. 9. A camera equipped with an electric film counter, characterized in that the power supply to peripheral circuits is stopped.