JPH02294628A - Camera - Google Patents

Abstract

PURPOSE:To execute a countermeasure to restore an action at the time of replacing a battery in a minimum memory area by providing a means for outputting a code showing that a film is being rewound, which has the code showing that the film is being rewound stored at a storage address in an EEPROM for storing data from starting rewinding the film till finishing it in the case of starting rewinding the film. CONSTITUTION:The means 3c for outputting the code showing that the film is being rewound is provided, which has the code showing that the film is being rewound stored at the storage address A in the EEPROM 2 for storing the data from starting rewinding the film till finishing it in the case of starting rewinding the film. Therefore, data communication for updating the counted number of the film is not executed at the time of rewinding the film. Then, a memory area where the code showing 'the film is being rewound now' is stored is also used as a memory area where the counted number of the film is stored, which is usually used as the memory area for storing the counted number of the film. At the time of rewinding the film, it is used as the memory area for storing the code showing 'the film is being rewound now'. Thus, the countermeasure to restore the action at the time of replacing the battery is performed in the minimum memory area.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention is directed to an E.I. EP
This relates to a camera with a built-in ROM.

(Background of the Invention) In recent single-lens reflex cameras and lens shutter cameras, an E
A device with a built-in EPROM is known. An example of a block diagram of this EEPROM built-in camera is shown in FIG.

In FIG. 4, numeral 1 is an MPU that controls the entire sequence of the camera, and 2 is an EEFROM . E is the battery that is the power source, s
w, SW, and SW3 are a release switch, a back cover opening/closing switch, and a film presence/absence switch, respectively. Also S
W5 is an analog switch, FCD is a film number display, PR is a power-on reset circuit, EC is a photometry circuit, S
D is an exposure control circuit that controls the shutter and aperture, FC is a distance measurement circuit, FD is a focus control circuit for automatic focusing, and WRM
is a feeding motor, and MD is a feeding motor drive circuit.

Note that PI-P3a of MPU1 indicates a signal input/output port, and CE of EEPROM2 indicates a chip enable signal, R
/W is a read mode/write mode switching signal, aO to a7 are 8-bit address buses that specify data addresses, and I/O. ~I/07 is an 8-bit parallel bus that inputs data.

In cameras with the above configuration, there are variations in the photometry circuit EC and distance measurement circuit FC due to the circuit configuration, so the output must be adjusted to the correct data by adding correction data specific to each camera. must not. EEPROM2
is for storing the correction data.

Incidentally, in addition to the correction data, the EEPROM 2 may also store the film count number. This means that even if the battery is replaced due to exhaustion or other reasons after loading the film and taking a few frames, the film count can be maintained by reading data from EEFROM 2 when inserting a new battery. This is to make it possible to return to the same state as before. Conventionally, even during film rewinding, the film count number is subtracted every time one frame is rewound according to the count from the film rewind counter at the film count storage address that stores the film count number. I was rewriting it. The flowchart of FIG. 5 shows a series of conventional operations from film loading to rewinding.

According to FIG. 5, first, the data DA of the film count storage address is roOJH (H: hexadecimal) in the initial state, that is, when no film is loaded, and immediately after loading the film. roIJH indicating that the next number of frames to be photographed is the first frame is written. The count is incremented by one each time one frame is photographed and rewinded, and rewinding begins immediately after the last frame is photographed. Then, the contents of the film rewind counter that started at the start of rewinding are rewritten to a value obtained by subtracting one from the data DA every time one frame is rewound, and DA = roo.
When the time reaches JH, it is assumed that the rewinding is completed, and the rewinding is stopped, the film rewinding counter is also stopped, and the initial state is returned.

Here, when the film count number storage address is set to address A, the time required for a 36-frame film to load the film, take a picture, wind the film, finish the picture, and finish rewinding the film is A.
Figure 6 shows the changes in address data DA. Here, the data DA is 8 bits, with the upper 4 bits indicating the tens digit of the film count number and the lower 4 bits indicating the 1 digit of the film count number.

However, in the above conventional example, if the battery is replaced during film rewinding, the EEPR is activated immediately after inserting the new battery.
Even if the film count data of OM 2 is read, it cannot be determined that the data is the count number during film rewinding. Therefore, in order to be able to rewind the film even if the battery is replaced during film rewinding, for example, a new EEFROM 2 must be installed.
A memory area is required within the camera to store the code "Rewinding film." In addition to this, the feeding motor WR
If M generates noise during rewinding due to duty drive or the like, there is a possibility that a communication error will occur when writing the count number for each frame of film during rewinding due to the influence of the noise.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems, to provide a camera that can take measures to restore operation when replacing batteries with a minimum memory area, and that can rewind film accurately. It is to provide.

(Characteristics of the Invention) In order to achieve the above object, the present invention provides a memory address in an EEPROM for data storage when film rewinding is started, from the start to the end of film rewinding. A rewinding code output means for storing a code indicating the inside of the film is provided, and data communication for updating the film count number is not performed when rewinding the film.
The memory area that stores the code indicating "Film rewinding" and the memory area that stores the film count number are both used, and is normally used as the memory area for storing the film count number. It is characterized in that it is used as a memory area for storing a code indicating "."

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is a block diagram showing an embodiment of the present invention,
Only the MPU3 differs from FIG.

The operation will be explained below using the flowchart shown in FIG.

First, if the film count number and film rewinding code storage address is address A, and the data at address A is DA (8 bits) as described above, the initial value roOJ H is stored at address A when no film is loaded. is written. Then, when the film is loaded (detected by the film state detection section 3a in Fig. 1), the next shooting is started.
Film count data roI indicating that it is a frame
Rewritten to JH (film count number update unit 3b
). And data D for each release and winding.
A is counted up one by one. Then, at the time when the end of the film is detected by the film state detection section 3a (for example, at the time when the shooting of the 36th frame in a 36-frame film is completed), the data DA is sent to the rewinding code output section 3c when the film is rewound. The rewinding code is rewritten to rFFJH, and film rewinding is started. At the same time, a film rewind counter starts.

Film rewinding is considered to have ended when this counter stops counting for a predetermined period of time, but until then the data DA remains rFFJH, and after rewinding is completed and the feed motor WRM is stopped, the initial value roO
Rewritten to JH.

FIG. 3 shows the changes in the data DA at address A during the time when the film is loaded with 36 frames according to the present embodiment, when the film is loaded and taken, when the film is wound and when the film is wound. Here too, the data DA is 8 bits and the upper 4
The bit indicates the IO digit of the film count, and the lower four bits indicate the 1 digit of the film count.

In the above configuration, if the battery is replaced before the shooting of one film is completed, for example, after shooting and winding the 28th frame of a 36-frame film, DA =
If the battery is replaced with r29J H rewritten, the EEPROM will be reset immediately after power is turned on with the new battery.
By reading the data at address A of No. 2, it is found that the next shooting count is the 29th frame, and it is possible to return to the state immediately before the battery was replaced. Also, if the battery is replaced while the film is being rewound, the data at the same address in EEPROM2 (rF
By reading FJH), it is known that the film was being rewound before the battery was replaced, and film rewinding can be started again.

Further, since communication with the EEPROM 2 is not performed while the feeding motor is rotating, data communication is not affected by noise generated by the feeding motor.

According to this embodiment, while the film is being wound up, the address in the EEFROM 2 where the film count number is stored is also stored as the film rewinding code while the film is being rewound. Measures to restore operation at the time of replacement can be taken with the smallest memory area. Furthermore, since data communication with the EEFROM 2 is not performed during film rewinding, communication failures due to motor noise do not occur. Therefore, it is possible to prevent the film from being unable to be rewound accurately.

(Correspondence between the invention and the embodiments) In this embodiment, the feed motor WRM and the feed motor drive circuit MD function as the film feeding means of the present invention, and the rewinding code output section 3c functions as the rewinding code output means. They correspond to each other. Further, address A corresponds to the film count storage address.

(Effects of the Invention) As explained above, according to the present invention, when film rewinding is started, film rewinding information is stored in the memory address in the EEPROM for data storage from the start to the end of film rewinding. A rewinding code output means for storing a code indicating the inside of the film is provided, and data communication for updating the film count number is not performed when rewinding the film.
A memory area for storing a code indicating "film rewinding" and a memory area for storing a film count number are used together, and are normally used as a memory area for storing a film count number.
Since the memory area is used as a memory area for storing the code indicating the code, it is possible to take measures for restoring operation when replacing the battery using the smallest memory area, and it is also possible to rewind the film accurately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing its operation, and FIG. 3 shows changes in data DA in the film count/film rewinding code storage address in this embodiment. 4 is a block diagram of a conventional camera, FIG. 5 is a flowchart showing its operation, and FIG. 6 is a diagram showing changes in data DA in a film count storage address in the conventional camera.

Claims (1)

[Claims] (1) In a camera equipped with a film feeding means for automatically winding and rewinding the film, and a data storage EEPROM having a storage address for storing the film count sent when the film is wound through data communication, At the start of film rewinding, rewinding code output means is provided for storing a code indicating that film rewinding is in progress from the start to the end of film rewinding at a memory address in the data storage EEPROM. camera.