JPS6396641A - E2 prom incorporated camera - Google Patents

Abstract

PURPOSE:To freely set film sensitivity by rewriting properly the film sensitivity area of an EEPROM properly through an internal microcomputer. CONSTITUTION:The film sensitivity is set by an SISO switch SISO for a film sensitivity change mode, a sensitivity reading circuit ISO which reads sensitivity out of a film cartridge freely, and an up switch Su or down switch Sd, the output of an AND circuit AN1 falls to L, and the microcomputer muC decides the rewriting of the film sensitivity and compares the contents of the sensitivity area of the EEPROM stored in a register with set sensitivity. Then when they do not match with each other, the contents of the sensitivity area of the EEPROM are changed into the set film sensitivity. Consequently, the film sensitivity of the EEPROM whose number of times of rewriting is limited is rewritten and changed properly and freely.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a camera controlled by a microcomputer, and particularly to a camera with a built-in E2PROM and a built-in E2PROM in which data related to the camera is written to the E2PROM. It is something.

[Prior Art] In recent years, various cameras have been commercially available that are equipped with a microcomputer and use this microcomputer to adjust the focus and control the exposure amount. In these cases, normal shooting information is stored in the RAM of the microcomputer. However, since the memory of RA~1 is erased when the power is turned off, photographing information such as the total number of shutter releases cannot be stored in the memory.

Of course, it would be possible to provide a backup power source for the RAM to retain memory, but in that case, it would be necessary to equip a backup battery, provide space for it, and increase costs. It will be up. In this regard, is electrically erasable and writable E2PROM a backup? Although it is advantageous because it does not require an II source, the E'PrtOM currently available on the market has a limited number of rewrites, and there are problems that need to be solved in the adoption and control of the E'F ROM.

JP-A No. 60-61731 has a built-in E2PROM that stores shooting information such as the number of films and data indicating the winding switch status when the power supply battery is removed or when the voltage drops.
A camera has been proposed in which data is written from AM to E2PROM and the written data is read out when a battery is attached. However, in the above camera, all data is written uniformly, and writing is not performed according to the contents of individual data.

[Object of the Invention] A basic object of the present invention is to provide a camera with a built-in E2PROM that allows rewriting according to the contents of data to be written. More specifically, the E2 captures the film sensitivity, which is important information for shooting but is often forgotten, and writes the film sensitivity to the E2PROM only when it is necessary to rewrite the film sensitivity.
The purpose is to provide a camera with built-in PROM.

[Structure of the Invention] Therefore, the present invention incorporates a control microcomputer and an E2PROM whose writing and erasing are electrically controlled by the control microcomputer. A memory area for storing the sensitivity is set, and a film sensitivity change mode setting means for setting the film sensitivity change mode, and a film sensitivity change mode setting means for setting the film sensitivity change mode, and a film sensitivity change mode setting means for setting the film sensitivity change mode by a predetermined external operation. A film sensitivity setting means for setting the film sensitivity, a rewriting determination means for determining whether or not to rewrite the film sensitivity memory of the E2PROM using the set film sensitivity, and a film sensitivity setting means for determining whether or not to rewrite the film sensitivity memory of the E2PROM using the set film sensitivity. and a writing means for writing the film sensitivity set by the setting means into the film sensitivity memory area of the E2PROM when the change mode is canceled, thereby controlling the writing of the film sensitivity into the E2PROM. E'P to do
It provides a camera with built-in rtOM.

In the present invention, when the film sensitivity is set in the film sensitivity change mode, the set film sensitivity is stored in the E2PROM.
l, :@ It is determined whether to write or not, and if it is determined that writing should be performed, the film sensitivity set in EfFROM is written when the film sensitivity change mode is canceled.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a circuit block diagram of an embodiment for achieving the present invention.

(E) is a battery that supplies power to each circuit, and (μC) is a microcomputer (hereinafter referred to as microcomputer) that controls the entire camera. A microcontroller (μ) that controls the entire camera
Flowchart 1 of C) will be described later. (E2P
ROM) is a ROM that can be electrically written and erased.It has a built-in voltage booster circuit, and when a write signal is input, it automatically erases the data and at the same time boosts the voltage to the voltage required for writing. Then, writing to the ROM becomes possible. (LMC) is a photometry circuit that measures the brightness of a subject, and outputs a digital signal indicated by the apex system as brightness information to the microcomputer (μC).

(LEC) uses a microcomputer (μC
) The lens circuit (AEC) that outputs to the microcomputer (μ
C) an exposure control circuit that controls the aperture and focal plane shutter based on the exposure information from (MOD);
) is a one-frame winding circuit that controls the motor to wind one frame of film, and (rso) is a film (hereinafter referred to as DX) in which film information such as film sensitivity and number of sheets is encoded and printed on the film container. When a film is used, it automatically reads the film sensitivity and outputs the digital signal indicated by the Apex system to the microcontroller (μC).It also automatically reads the number of sheets of the film and sends it to the microcontroller (μC). This is a film sensitivity reading circuit that outputs to μC). (DISP) is a display device that performs various displays based on signals output from a microcomputer (μC). (BC) detects battery voltage and prevents camera malfunction when the voltage falls below a predetermined voltage. When this battery check signal is input to the microcomputer (μC) in the battery check circuit that stops camera control, the microcomputer (μC) executes the interrupt routine BAT (described later).
Execute the INT flow. (DC-DC), when the battery voltage drops, the microcomputer (μC) and E2PRO
This is a converter circuit that supplies stable 5-inch power to M.

Next, to explain the signal lines between the microcomputer (μC) and the E2F ROM, the microcomputer (μC) and the E2PROM are connected to an address bus (ADo~7) that specifies the ROM address of the E2PROM, and an address bus (ADo~7) for exchanging data. data bus (00 to 7), W/n control line (W/I" () that transmits read and write signals, and chip enable line (GE) that transmits a signal that starts read and write control.
, and are coupled by a Write Busy line (W-Bu) that transmits a Write Busy signal indicating that writing is in progress, and each device is provided with the necessary terminals. (Tri) is a power supply transistor that supplies power to devices other than the microcontroller (μC) E2PROM and display device (DISP); (RR) and (OR') are microcontroller (μC)
Resistor and capacitor, CDI) to reset the
(D2) is a diode for preventing reverse charging, and (CyL) is a crystal oscillator that supplies a clock to the microcomputer (μC).

Next, to explain the switches, (Sl) is a shooting preparation switch that is turned on by pressing the first release button (not shown), (SISO) is a film sensitivity change switch for changing film sensitivity; The film sensitivity setting value is changed by pressing S (so) and the up, down switches (Su), (Sd) described later. Also, when either the shooting preparation switch (Sl) or the film sensitivity change switch (SISO) is turned on, the output of the AND circuit (ANI) goes to High level (
The microcomputer (7zC) performs a predetermined operation.

(S2) is a release switch that is turned on when the release button is pressed for the second time (more than the first press).
C) is r H-! by turning on this switch. When a signal changing from the level to the rLJ level is input, a release routine is executed, and exposure control and subsequent film winding control are performed. (S3) is O when the exposure is completed.
Press the exposure completion switch to N while the film is being wound.
It is turned off by a charging mechanism (not shown). (S4) is turned off by a mechanism (not shown) due to ONL and release when the piece winding is completed. (S5) is a back cover close detection switch, which turns on when the camera back cover is closed.
When the signal that changes from rHJ level to rLJ level due to this ON is input to the microcomputer (μC), the microcomputer (μC) executes the back cover ON interrupt routine described later and performs predetermined control. . (S6) is a film detection switch that detects the presence or absence of film. It is turned OFF when the film is wound around the spool. (Su).

(Sd) is an up/down switch, and when going up (advance) or down (move down) the information you want to change, you can turn the information up or down by turning it on along with the switch for the information you want to change. .

Next, the operation of the camera is explained by the microcomputer (μ
This will be explained with reference to the flowchart of C).

Battery replacement> When the battery is replaced and a new battery is loaded into the camera, rLJ is connected to the reset terminal (RE) of the microcomputer (μC) through the reset resistor (RR) and capacitor (CR).
When a signal changing from the level to the rHJ level is input, the microcomputer (μC) executes the flowchart shown in FIG.

First, the microcontroller (μC) resets all internal registers and flags, and outputs the output terminal (0) and port (OP
) to the rLJ level (#5.#lO).

Next, the data stored in the E2PROM is taken into the internal register (#+5). This data acquisition is performed by executing a subroutine shown in FIG. Before explaining this subroutine, let us first explain the E2PROM address and the data input to this address.
The explanation will be based on the table. In addition, the microcontroller used (
μC) and E2PROM have an 8-bit configuration.

Table 1 First, E2PROM address r00J number M? In this case, the total number of times the release was performed was approximately 10,000 ri, and (bo, bl, b2) = (0, 0, 0).

(1,0,0), (0,1,OXI,l,OX☆,☆
, 1), if the total number of releases is N, then N≦1, respectively.
Ten thousand.

10,000<N≦20,000, 20,000<N≦30,000, 30,000<N≦40,000.

N>40,000. This is used to alleviate the memory limitations of rewriting the total number of releases due to the limit on the number of times E2PROM can be rewritten, or rewriting the number of film shots taken. Specifically, the number of rewrites is guaranteed to be 10,000 times. The unit of rewriting is detected using the above bits, and if it is detected that rewriting has been performed 10,000 times, the rewriting byte (address) is changed. Addresses (01), (11), (21), and (31) are supposed to store the contents of the lower 8 bits of the total number of releases, and if the number of releases is less than 10,000, address (01) memory for address (11) for more than 10,000 but less than 20,000, and memory for address (11) for more than 20,000 and less than 30,000.
21) memory, address (3
1) memory is used. Address (02), (12)
, (22), and (32) show the top 8 in terms of total number of releases.
The contents of the bit are memorized and the address (OI), (
16 in pairs with I), (21), and (31), respectively.
It is used as a bit configuration, and the memory addresses used for the total number of releases at that time are (01), (11).
, (21), and (31). Address (03),
(+3), (23), and (33) store the number of film sheets that have been shot, and as mentioned above, they can be used depending on the total number of shutter releases. Address (04) stores the film sensitivity. Since the film sensitivity is changed (rewritten) less often, no spare bytes are provided.

Returning to the flowchart, the flow of the data reading subroutine from the E2PROM shown in FIGS. 3(1) and (II) will be explained.

First, the microcomputer (μC) prohibits all interruptions to this flow during data reading so that the data does not become incorrect data (#100). Next, a subroutine for reading data from the E2PROM is executed by setting the address "0" of the data to be read (#105.#110
). This subroutine is shown in FIG.
(Set the signal to "■-u" level to set the read mode (from the microcontroller's perspective) #255), set the chip enable terminal (CE) to "■]" level (#260),
'Latch that the PROM is in the data read mode of the above address. The E2PROM internally decodes the latched address and stores the data at that address (D
A) is output to the data bus, and the microcomputer (μC) manually inputs this data (DA) (#265). In this flowchart, the microcomputer (μC) outputs the chip enable signal (CE) and immediately inputs data (DA), but if the processing speed of the microcomputer (μC) is fast, the chip enable signal After outputting (CE), a time waiting step may be provided. Data (D
After inputting A), the microcomputer (μC) sets the chip enable signal (GE) to the rLJ level to finish reading 1 byte of data (#270), and returns (3rd step).
Proceed to step #I15 in Figure (1)). Next, in step #l15, this data (D A) is output to the register (0), the bt and bo of the data are determined, and the E'Pr where the data of the total number of releases and the number of film shots taken is stored. (Detects the address of OM.

First, in step #120, (b I , bO) = r00
If it is determined to be J, as explained in Table 1, the number of rewrites (N) is 10,000 or less, so step #125
The addressing variable R1 is set to 1. (bl.

When bO)=r01J (#l30), 10,000 times N≦2
Since it is 10,000 times, 111 is I 1 (# 135), (
bl , bO) = rl When OJ (#135), 20,000 times <N≦30,000 times, so R1 is set to 21 (#145), (
bl, bo)=rll'', R1 is set to 31 because N is 30,000 times and N≦40,000 times (#150). This address designation variable R1 indicates the address where the lower 8 bits of the total number of releases are stored. Next, set the register specification variable R2 to "l"(#155), set the address to the above R1 (#160), and first read the lower 8 bits of the total number of releases from the E2PROM (#l65). Store data DA in register (1) in microcomputer (μC) #170). and,
Add “1” to the addressing variable R1 and create a new R
1 (#l75), add "bi" to the register specification variable R2 and set it as a new R2 (#180), and set R2 to "4".
” (# I 85), the data of the upper 8 bits of the total number of releases is stored in the E2PROM.
Read the data from the E2PROM to the register (2), and read the data of the number of film shots taken from the E2PROM to the register (3).
(#160 to #185). Next, the microcomputer (μC) sets address R1 to "4" in order to read the sensitivity data of the remaining film from the E2PROM.
Set it to #l90) and read the data (#195)
After storing this data (DA) in the internal register (4) (#200), interrupts are enabled and the process returns (#205). This completes the reading of E2PROM data into the register.

When this reading is completed, the microcomputer (μC) proceeds to step #20 in Figure 2 and checks whether either the shooting preparation switch (Sl) or the film sensitivity change switch (SISO) (SA) is turned on Determine whether When both switches are OFF, the end flag (EN
DF) is set (#25), and if it is set, the process returns to step #20; if it is not set, the power supply transistor (Tri) and the DC-
Terminals (01) and (03) to turn off the DC converter
to the rLJ level (#30, 35). Then, the end flag (ENDF) is set, all displays are turned off, and the process returns to step #20 (#40.#42).

In step #20, if either the shooting preparation switch (Sl) or the film sensitivity change switch (SISO) is turned on, the process advances to step #15, where the end flag (ENDF) is reset, and then Reset and start the timer (#50). This timer is a hard timer built into a microcomputer (μC) and is used to maintain power. Reset the timer and start the power supply transistor (T r
1), set the terminal (01) to rHJ level (#55). Next, set the terminal (03) to the rHJ level and turn on the DC-DC converter (#60).
Enable power to be supplied to the PROM. Then, it is determined whether or not the film sensitivity change switch (SISO) is turned on (#65), and if it is turned on, the process proceeds to a film sensitivity change (ISO change) subroutine (#70).

<rso change> This ISO change subroutine is shown in Fig. 4 (I) and explained. First, the contents stored in the Sv register (SvR) are read out, this is set as Sv (#300), and this value is displayed. Output to device. The display device (DISP) is
Among the displays shown in FIG. 4 (If), the film sensitivity is displayed using only "ISO day, day, roll"(#305). Note that this Sv is displayed as an apex value. Next, the microcomputer (μC) controls the film sensitivity change switch (SIS).
If it is ON, determine whether either the up switch (Su) or the down switch (Sd) is ON (#310).
315° #325), and when the up switch (Su) is ON, the film sensitivity (Sv) is increased by 0.5.
(#320), and when the down switch (Sd) is ON, subtract 0.5 from the film sensitivity (Sv) to obtain the new film sensitivity (Sv) (#330)
).

The process then proceeds to step #335, waits for a certain period of time to avoid continuous changes, and then returns to step #305.

If neither the up switch (Su) nor the down switch (Sd) is turned on, the process returns from step #325 to step #305 and this flow is repeated to display the film sensitivity. In step #310,
The microcontroller (μC) controls the film sensitivity change switch (SIS).
When detecting that the S register (O) is turned off, the S register (
Film sensitivity (SvR) stored in memory (SvR)
Determine whether the changed film sensitivity (Sv) and the changed film sensitivity (Sv) are equal or not (#340); if they are equal, return to the flow above; if not, the changed film sensitivity (Sv)
In order to write to the E2PROM, the process advances to the ISO write subroutine (#345) and returns after writing is completed.In this way, the changed film sensitivity (S) and the film stored in the E2PROM are sensitivity(
By not writing to the E2PROM when SvR) is equal and reducing the number of writes, the E2PROM
It is possible to effectively deal with the limit on the number of writes.

Next, to explain the ISO writing subroutine shown in Figure 5, first change the changed film sensitivity (Sv) to SV
E2r' to be memorized and written to register (SvR)
Set the ROM address to "4", set the contents (SvR) of the SV register (SvR) in the data output register, and proceed to the write subroutine (#365).
Returns after writing is completed.

The above-mentioned writing subroutine is shown in FIG. 6 and explained. First, the microcontroller (μC) prohibits data destruction by prohibiting interrupts that occur during writing (#
400). Then connect the write/read terminal (W/R) to f'
Set it to LJ level (#405), set it to write mode, and output the data at the address "4" set above (#41
0. #415). Next, the deep enable (GE) is set to the "11" level to start writing to the E2PROM (#420.#425). During writing to E2PROM, “Write Busy terminal (W-Bu)
It outputs "H" level, and when writing is completed, it outputs rLJ level. The microcomputer (μC) recognizes this termination signal as rL.
Wait until it reaches J level (#430), and when this signal is detected, set the deep enable to rLJ level 1#4
35), output write mode end to E2PROM,
Allow interrupts and return (#435). Note that in a device that does not have the W write Busy terminal (W - B Ll), the time required for writing may be measured and the device may wait for this time.

This completes the ISO change subroutine.

<Preparation for photographing> If the film sensitivity change switch (SISO) is not turned on at step #65 in FIG. 2, the process proceeds to a subroutine for preparing for photographing (SION).

This subroutine is shown in FIG. 7 and explained. The microcomputer (μC) controls the photometry circuit (LMC) and lens circuit (LEC), which are driven by turning on the power supply transistor (Tri).
), respectively input the aperture photometric value (Bvo) and the lens-specific aperture value (Avo) (#450° #455).

Next, check whether the film is loaded or not #46
0), if loaded, film present flag (FTLP
), and if it is not loaded, reset the flag (FrLF) (#470).

Then, the film sensitivity (SvR) stored in the SV register (SvR) is output (#475), and a predetermined exposure is calculated from the above-mentioned aperture metering value (Bvo), lens aperture value (AvO), and film sensitivity (Sv). (#4
80), the shutter speed, control aperture value, and number of film shots obtained through this calculation are sent to the display device CDl5P), and the rTv
EE day QO, AVE, EE, EE" is displayed and the process returns (#490).

Returning to Figure 2, when the microcomputer (μC) finishes the ISO change or 5ION subroutine (#70.#75), it turns on either the shooting preparation switch (Sl) or the film sensitivity change switch (SISO). (#80) If either one is turned on, the process returns to step #45 and repeats the routine.

If both switches (S 1 ) and (STSO) are OFF, it is determined whether the timer started in step #50 has elapsed for 10 seconds (#85),
If 10 seconds have elapsed, the process advances to step #30 to complete the photographing process; if 10 seconds have not elapsed, the process returns to step #55, repeats the routine, and waits for the shutter release.

Shutter Release> Next, when the release switch (S2) is turned on, the microcomputer (μC) performs the control process for photographing shown in FIG.

First of all, the microcontroller (μC) uses the battery replacement interrupt BATIN
Interruptions other than T are prohibited (#500), and the release operation and exposure are controlled (#505). Exposure control is performed by sending a running start signal for the front curtain (first curtain) and rear curtain (second curtain) of the focal brain shutter to the exposure control circuit. When the exposure ends (#510→#5
12), the exposure completion switch (S3) indicating this is ONL.
When the ON signal of this switch (S3) is input, the microcomputer (μC) changes the address "0" in the microcomputer (μC).
It is determined whether bit b of the register has exceeded 2 months, that is, the number of rewrites (N) has exceeded 40,000 times (#512), and if it is set, the subsequent data will be reliable even if the contents of the E2PROM are rewritten. If not, the process proceeds to step #570, a film winding subroutine, without rewriting. This subroutine will be described later. Bit b above
2 is not "beat", the microcontroller (μC) sets the lower counter (CNTr(1)) of the internal total number of releases as "
1” (#515), and this value is “0”, that is, the lower 8
Check whether there is a carry from bit #520
), if there is a carry, the upper counter (CN
TR2) is added with "BI"(#525).Then, the process proceeds to the address change subroutine (#530) that specifies the address to be changed depending on the degree of writing.Even if the lower counter (CNTR1) is not "0" Proceed to address change subroutine.

FIG. 9 shows this address change subroutine, and to explain it, the microcomputer (μC) determines whether the contents of the upper and lower counters (CNTR2, CNTR1) are less than 10,000, and if the contents are less than 10,000. If there is, set the addressing variable R1 indicating the address for writing the total number of releases to “
Set to B and return (#600 to #605)
.

If the content of the counter (denoted as N) is 10,000 and N≦20,000, the microcomputer (μC) executes the steps starting from step #615. At step #615, the bits (bO, bl) indicating the total number of releases in 10,000 are set to (0, 0
).

(0,0), the first total number of releases exceeding 10,000 times, that is, 10,001 times, is assumed to be bit (
bo, bl) to (0, 1), set the data transfer register to "bi," that is, (bO, bl) = (0, 1), and set the address of E"Pr (OM to "0, ”, go to the write subroutine and write this (
#620~#635).

Next, address designation variable R for writing the total number of releases.
Set 1 to 11 and return (#640). Even when the bits (bO, bl) are not (0, 0), the process proceeds to step #640 and similar processing is performed. Microcomputer (μ
C) The content of the counter (CNTRIXCNTR2) is 2.
10,000〈N≦30,000, 30,000〈N≦40,000, the above 10,000〈N
≦20,000, perform the same processing. If the counter content is 20,000 and N≦30,000, then the bit content (bO, bl) = ('
0. l), and if (0, 1), then 2
If the number exceeds 10,000, set this as (1, 0), set the address to "0", proceed to the write subroutine, and E"P
Write to ROM and set addressing variable R1 to “
Set to 2 bits and return (1650-675).

If the bits (bO, bl) are not (0, 1), set the addressing variable R1 to "2bit" and return.Similarly, if the contents of the counter (CNTRIXCNTR2) are 30,000 <N≦40,000 , the contents of bits (bO, bl) are (
1, 0), and if it is (1°0), it exceeds 30,000, and the above bit (bO, bl) is set to (1, 1).
), set the address to "0', and proceed to the write subroutine to write to the E2PROM (#6B5~
#705). Then, set the addressing variable R1 to “3 bits” and return (#710). Bits (bO, b
l) = (1, 0), set addressing variable R1 to "3 bits" and return. Counter (CNTR
1, ), (CNTR2) exceeds 40,000, the microcomputer (μC) (7) 7 address 0 bits (bO, b l
, b2) are set to (0, 0, l), the warning display data is output to the display device, and the data is set to "4"(#715 to #725). Then, set the address to “0” and transfer the bits (bO, bl,
b2) data and set addressing variable R1 to “3”.
Set it to B and return. This warning is displayed on the assumption that the release operation has been performed 40,000 times, so that the camera can be inspected at a service station. Note that this number is not limited to 40,000 times, but may be tens of thousands of times, and if it is 50,000 or more, the memory for rewriting the release of the E2PROM may be increased accordingly.

Returning to FIG. 8, the microcomputer (μC) sets the address specification variable R1 in the address register, first sets the contents of the lower counter (CNTRI) as data, proceeds to the write subroutine, and writes the data ( #535
~545). Next, add "bi" to the above address specification variable R1 to make it the E2PROM address for the upper bit, set this in the address register, set the contents of the upper counter (CNTR2) as data, and perform the write subroutine. Proceed to and write the data (#550 to #5
65).

After rewriting the data, the microcomputer (μC) performs film winding processing (#570).

<Film Winding> The winding subroutine is shown in FIG. First, the microcomputer (
μC) outputs a signal to turn on the winding motor (M) from the terminal (02) to the winding circuit (MOD) (#750, #755) by disabling interrupts other than the back cover and battery replacement interrupt (BATINT). ).

Then, it waits for the winding to be completed (#760), and when the winding completion switch (S4) is turned on, this is detected and a signal to stop the motor is output (#765). Next, determine whether or not there is film by checking whether a flag (FILF) indicating this is set (#770), and if it is set, bit b2 of address (0) in the microcontroller.
Determine whether the film is “V” (#773). When there is no film or the number of rewrites (N) of the E2PROM is
If the number exceeds 1,000,000 times (b2=1), the number of films that have been photographed is not rewritten as shown below, but an interrupt is permitted and the process returns (#772). There is a film,
If the number of shots has not exceeded 40,000 times, in step #775, 1 is added to the variable NR indicating the number of film shots taken, and "2" is added to the address designation variable R1 to obtain the address for writing the number of film shots taken (#780). ). Then, set the addressing variable R1, set the data NR, proceed to the write subroutine (#795), write the number of exposed films to the E2PROM (,:, and return (#790).
~#795).

<Closing the back cover> Next, the microcomputer (μC) shown in Figures 11 and 12 shows how the camera operates when the back cover changes from the open state to the closed state.
This will be explained with reference to the flowchart.

When the back cover is closed, the back cover close detection switch (S5) turns O.
When a signal that changes from the "H" level to the "L" level is input to the microcomputer (μC), the microcomputer (μC) executes the back MOH writing routine shown in FIG. First, the microcomputer (μC) detects whether or not film is loaded (wound around the spool) in step #800. If film is loaded, the back cover has been opened by mistake. As such, the process proceeds to step #815 without performing initial loading. If no film is loaded, the process proceeds to the initial loading (initial winding) subroutine (#805).

This initial load subroutine is shown in FIG.
To explain, first, the microcomputer (μC) sets the variable indicating the number of exposed films NR to "0", and then starts the winding motor (M).
Outputs a signal to turn ON and starts winding (#9
00. #905). Wait until the winding is completed in step #910, and when the winding is completed, the above variable NH is set to “
1" and repeats the above winding operation until the variable NR becomes 3 (#915, #920). Then, when the variable NR becomes 3, that is, the initial winding is completed, the winding motor (M) is stopped. , reset the variable NR to "0" and return (#925.#930).

Returning to Figure 1I, after completing the initial load process (#805), the microcomputer (μC) should determine whether the film is loaded (#810), and if so, set the flag (FILF). #815), and detects whether the film is a DX film whose film sensitivity is formed by an electrical pattern on the container (#825).

This detection can be performed using a well-known method, specifically, for example, by determining whether at least one of the lower two bits indicating the film sensitivity is electrically connected to a common terminal on the film container. The film used is DX
When it is film, the film sensitivity Sv is automatically read and data indicating this value is output to the display device (#830, #840). Note that when no film is loaded, the film flag (FILF) is reset (#820). Also, if no film is loaded, or if it is not a DX film even if it is loaded, the film sensitivity (SvR) stored in the register will be set to SvR.
v (#835), and outputs this value to the display device to display it (#835.#840). Next, the memorized film speed (SvR) and the above film speed (
Sv), and if they are not the same, the process proceeds to the ISO writing subroutine (#850) and writes the film sensitivity (Sv) to the E2PROM (#845.#850). If they are the same, skip step #850 and execute E2PR.
Proceed to step #855 without writing to OM, determine whether the end flag (ENDF) is set, and if it is set, return to the SA routine; if not, return to the step before the interrupt. .

Next, the battery voltage drops and the microcomputer (μC), E2PR
When the voltage is slightly higher than the voltage that causes the OM and other circuits to malfunction, a signal indicating this is input from the battery check circuit (BC) to the microcontroller (μC), and the microcontroller (μC) B'ATINT not shown
Execute the routine. The microcomputer (μC) sets all output terminals to the rLJ level and stops (#950).

Stopping here refers to control that also stops the clock.

<Second Example> Next, a second example will be shown. In the above embodiment, the total number of releases is always written to both the upper 8 bits and the lower 8 bits, but even though the upper 8 bits are changed only once every 256 times, it is a processing problem to rewrite them every time. Not only does it take a long time, the current consumption (power) increases, and furthermore, due to the limit on the number of rewrites, a plurality of spare memories are required within the E'PROM. The purpose of this modification is to eliminate these drawbacks, and the upper 8 bits are
It is now possible to rewrite only when the bit contents change.

In this embodiment, the contents of the E2PROM memory were changed in accordance with the change, and these are shown in Table 2, and only the changes will be explained.

First, the upper 8 bits of data indicating the total number of shutter releases are stored at address "00" of the E2PROM. In this case, as mentioned above, rewriting occurs once every 256 times, so even if you count up to 40,000 times, for example, 40,000/2
56 = 156.25 (156 times) rewriting is performed, and no spare byte is required to limit the number of rewrites (10,000 times).

Other changes include the elimination of the E2PROM addresses (02, 12, 22, 32) and the elimination of the address (00) shown in Table 1.
This is because an attempt was made to determine the total number of releases based on the top 8 bits of the total number of releases. Changes to the microcomputer (μC) flowchart for executing these steps are shown in FIGS. 14 to 16.

FIG. 14 of Table 2 is a modification of step #15 shown in FIG. First, in step #1000, all interrupts are prohibited and the address for E2PROM is set to "00" (
#1005). And the content DA corresponding to this address
is read from the E2PROM and sent to the microcontroller (μC
) to the register address “0” (#10
10. #1015).

The content of this counter (CNTR2) is decoded, and when this value is 39 or less (9984 times), the addressing variable R1 is set to "BI(#1020.#1025)", and similarly the content of the counter (CNTR2) is 78 or less (9984 times). 19968 times), set the addressing variable Rf to 'I (#1030, #l0
35), the contents of the counter (CNTR2) are less than or equal to 17 (
29952 times), set address specification variable R1 to “2bit (#
1040. #1045), if the content of the counter (CNTR2) is 156 or less (39936 times), set the addressing variable R1 to "3 bits"(#1O=17.#1050) and proceed to step #1055.The content of the counter (CNTR2) exceeds 156, the display device ('
DISP), and the process proceeds to step #1090 without rewriting the E2PROM. The following is Figure 3 (1)
However, due to the change in the contents of the E2PROM memory, step #1075 corresponding to step #175 is changed to R1←R1+2, and furthermore, in step #1090 corresponding to step #180, the address is changed. It has been changed to 4″.

FIG. 15 is a modification of the release routine shown in FIG. First, the microcontroller (μC) prohibits interrupts other than BATINT and performs exposure control (#l 150
．． #1155). When exposure control is completed (#1160)
If the upper 8-bit counter (CNTR2) exceeds 156, output data that displays a warning that the E2PROM rewriting limit has been exceeded and proceed to the film winding subroutine (#f170→#I240). .

If the above counter (CNTR2) is 156 or less, add “bi” to the lower 8 bits of the counter (CNTRI),
It is determined whether this value is "0", that is, a carry to the higher order has been performed (#I 175. #1180). This value is “0”
”, assuming that a carry has been performed, add “ to the upper 8 bits of the counter (CNTR2) and convert this to E2.
Set it in the PROM output register and set the address to “0”.
is set in the address register, proceeds to the write subroutine, writes to the E2PROM, and proceeds to step #1205 (#If85 to #t 2 Q O
).

If the counter (CNTRI) above is not “0”, only a carry has been performed, so the upper 8 bits must be changed and the E
The program proceeds to step #I2O3 without rewriting the 2PROM.

Next, the microcontroller uses the upper 8-bit counter (CNTR2)
Check the content of the counter, and if this content is 39 or less, set the addressing variable R1 to "BI (step #1205.#I2
10), if this content is 78 or less, address specification variable R1
"11" (steps #1215, #]220), and if this content is less than 117, set the addressing variable R1 to "21" (step #1215, #]220).
Steps #1225, #1230), this content is 117
If it exceeds, set the addressing variable R1 to "3 bits (step #1235), set the lower 8 bits of data and address R1 to the E2PROM output register,
Write and proceed to winding (#1245 to #I
26Q).

FIG. 16 shows a subroutine that performs this winding process, but instead of step #773 shown in FIG. At this time, proceed to step #1130 and record the E2P of the number of shot films.
After rewriting to the ROM, if the number exceeds 156, the process proceeds to step #1355 and the E2PROM is not rewritten. Other than that, it is the same as FIG. 10.

Third Embodiment In the third embodiment shown below, the timing of writing the total number of releases and the number of exposed films to the E2PROM is
This is done at the timing of the 0FF (start of second curtain travel) of the second curtain of the shutter. The reason for this is that from the start of the second act to the end of exposure (second act completion),
Since there is no need to perform any camera control and there is idle time, the sequence control can be carried out more efficiently by writing to the E2PROM using u2 at this time. This is especially effective during continuous shooting. Figure 17 shows the flowchart in that case.

It is shown in FIG.

Fig. 17 is a modification of Fig. 15. When the release operation starts, the microcomputer first prohibits interrupts to this flow other than BATINT (# l 150), and then controls the exposure control circuit (ABC). and performs the release operation (operation up to the start of exposure R such as mirror up) (#1151') (This can be done by timer control or by providing a switch that detects the completion of mirror up, and by this, the release operation can be controlled. Good), then the first act of Focal Brain Yatter 0FFL (start of first act running) (# + ! 52') 1.
After the exposure time has elapsed (#1153'), the second curtain is turned off (second curtain running starts (#1154').

Next, write the total number of releases to E2PROM (#1
After performing steps 170 to #1255X (explanation omitted), in step #1400, the number of exposed films is written into the E2PROM. Then, it waits for the exposure to be completed (the second curtain has run), and when the exposure is completed, it controls winding and proceeds to the SA routine (#1403, #1406, #1410
．． #1413. #1420).

FIG. 18 shows a subroutine for rewriting the number of exposed films. This is the film winding routine part (# I
300 to #l315), and the corresponding step numbers are given and duplicate explanations will be omitted.

<Fourth Example> In the fourth example shown below, instead of writing the total number of releases each time, a certain number of times is taken as one unit, and the number of times in this unit is written. I decided to go. By doing this, the need for a spare byte is eliminated, the current consumption is minimized, and the time required for this (writing to the E2PROM) is shortened.

However, in this case, when the battery is removed, the microcomputer (μ
Since the total number of releases stored in the register in C) is erased, the number of releases that do not reach 1 unit is canceled and becomes "0", and this erased number of releases is an error from the correct total number of releases. However, 1
Since the number of times the battery is converted within 10,000 shots is known, this is not a large error. For example, if the number of releases per unit is "5" and a new battery is inserted, the number of shots that can be taken with this battery is 500 (20 with a 24-exposure film).
If we assume that out of 10,000 shots, the battery must be replaced 20 times, and the average number of shots canceled when replacing the battery is 2.5, then 20 x 2.5 = 50 is the error within 10,000 shots. This results in an error of only 0.45%.

In this fourth example, E
The changes to the 2PROM address and its contents, compared to Table 2, are the lower 8-bit spare byte addresses (1, 1) and (21) of the total number of releases.

The difference is that (31) and the memory required for it are deleted, but other than that, they are the same.

Figures 19 to 21 show the microcomputer (μ
A flowchart of C) is shown. Figures 19 to 21 are
This corresponds to FIGS. 14 to 16 showing the third embodiment, respectively.

First, referring to FIG. 19, the microcomputer (μC) disables all interrupts (#2000) and steps #2005.
~In step #2030, the data of the upper 8 bits and lower 8 bits of the address rOJJIJ stored in the E2PROM are read, and the data is stored in a predetermined register rOJ,
rlJ (hereinafter these registers will be referred to as counters (CNTR2) (CNTR1)).

Now, if the number of releases per unit mentioned above is "5", then
The number of releases reaches 10,000 when the value of the register (counter (CNTr(I), (CNTR2)) reaches 2,000.

The microcomputer (μC) decodes the contents of the counter, and when the value is less than "24", the value of the counter is less than 2,000 (less than 10,000 times), so it sets the addressing variable R1 to " 3” (#2035→#2040)
, when the decoded value of the counter is less than "44", the value content of the counter is less than 4,000 (less than 20,000 times), so address designation variable R1 is set to 13"(#2045
→ #2050), the decoded value of the above counter is “64”
If the value of the counter is less than 6,000 (less than 30,000 times), the addressing variable R1 is set to "23"(#2055→#2060), and the decoded value of the counter is "84" or less. At some point, the value of the counter is less than 8,000 (less than 40,000 times), so the addressing variable R1
are set to “33” (#2085), and E2
Read the PROM data DA (number of films) #
2090), stores this in a predetermined register (R2) (#2095), and proceeds to step #2100. When the content of the counter exceeds 8,000 (40,000 times), warning display data is output to the display device and the process proceeds to step #2100 (#2097). Next, the microcontroller (μC) sets the address to "4", reads the data from the E2PROM, and stores it in a predetermined register (42100~
#2110). And the variable K for counting one unit is O
, enable interrupts, and return (#211
5. #2220).

Next, the flowchart shown in FIG. 20 corresponds to the flowchart shown in FIG. 15, and the change is that step #1170 in FIG.
After this step, three steps for determining whether the number of releases has reached the monthly unit are added, and steps #I2O3 to #1235 are replaced with step #23.
20 to #2350, and step #I250 was changed to step #2355. Starting from the top, in this fourth embodiment, writing is performed once after the release has been performed five times, so the counter contents are 8,000 or less (
40,000 times), and if it exceeds 8,000 times, a warning is displayed (#2358).

If it does not exceed 8,000, add 1 to the variable K for determining 1 unit and create a new K (#2305), which becomes "5".
It is determined whether it has become (#2310).

If this variable K is less than 5, the E2PROM is not written and the process proceeds to the winding subroutine to perform winding processing (#2360). If variable K becomes “5”, set it to 0
''(#2351), and writes to the E2PROM (#2311 to #2316).

As mentioned above, since writing is performed once when the total number of releases is 5, the contents of the counter in units of 10,000 times are changed, and this counter (CNTRl, C
When the decoded value of NTR2) is “24” or less, set addressing variable R1 to “3” (#2320→#2325)
, when the decoded value of this counter (CNTR1, CNTR2) is “44” or less, address designation variable R1 is set to “13”.
” (#2330-#2335), this counter (CN
When the decoded value of TRI, CNTR2) is less than “64”, address specification variable R1 is set to “23” (#2340-
#2345), this counter (CNTR1, CNTR2
) exceeds "64", the addressing variable R1 is set to "33"(#2350). Note that this addressing variable R1 is equal to E, which is the number of exposed film sheets.
This is the address of 2PROM. After setting address specification variable R1, lower 8-bit counter (CNTRI)
Set the data in the E2PROM (#2352), set the address to "B"(#2355), proceed to the write routine, and write the set data to the E2PROM (#2357).
, executes the post-write winding subroutine (#2360).

The flowchart in FIG. 21 corresponds to the flowchart shown in FIG. 16, except that step #1335 for setting the address value is deleted and step #1325 is changed to step #2360. This is the same as the flowchart.

This change is due to the fact that writing is performed once when the total number of releases is five, and the other steps will be given corresponding step numbers in FIG. 16 and their explanation will be omitted.

<Fifth Example> The fifth example shown below attempts to count the total number of releases using the number of films used. Specifically, when a film is loaded, The number of films of the film is read from the pattern electrically indicating this, and the total number of releases is normalized by this number. The number of films for this standardization is 12, and the total number of releases (12) is taken as 1 unit, and " is added to the counter. In other words, in this example, the actual number of releases is not counted, but is replaced by the number of films. , furthermore, the fourth
In the embodiment, one unit is 5 times of release, whereas 1 unit is 12 times.

Therefore, the count value for 10,000 releases is 83.
3 (actual total number of releases is 9996), and similarly, 20,000 times is +666 (19992) as a count value.
), 30,000 times is counted (2499 (2998
8), 40,000 times is 3332 (3998) as a count value.
4). In addition, it is counted at 30,000 times (as a direct person, it is 25
00, but if we set it to 2500, the number between 20,000 and 20,000 times becomes 18, which exceeds 10,000, so we decided not to use it.

The flowchart for implementing this is shown in Figures 22-2.
It is shown in Figure 5.

The flowchart in FIG. 22 corresponds to the flowchart in FIG. 19, and since the units of normalization of the number of rewrites are different, step #2035 and step #20 in FIG.
45. Step #2055゜ Change the numerical value in step #2065 to step #2400, step #2410. Steps #2420 and #2430 are changed to the count values as described above, and the other steps are given the same step numbers as in FIG. 19, and their explanation will be omitted. Note that the resetting of variables in step #2+15 in FIG. 19 is omitted because it is unnecessary in this embodiment.

In this case, the number of films can be read in the back cover opening subroutine (see FIG. 1I) which is executed when a new film is loaded and the back cover is closed. The flowchart shown in FIG. 23 is a subroutine for reading the number of film sheets (
#2440) is added, and the other steps are the same as in FIG. 11, so the same step numbers are assigned and the explanation will be omitted.

This subroutine is shown in FIG. 24 and explained. First, the microcomputer (μC) determines whether the count value is 3332 or less (the total number of releases is approximately 40,000 or less), and if it exceeds this, the microcomputer (μC) CNTR1), (CNTR
2) Outputs the warning display data to the display device and returns without rewriting the contents (#2450.#245
2).

If the counter value is 3332 or less, step #24
At step 53, it is determined whether or not it is a DX film, and if it is not a DX film, the number of frequently used films is set and the process proceeds to step #24.80. Currently, the most commonly used film is the one with 36 exposures, so we set the number of films to 36 and enter "in the counter (CNTRI)".
Add 3”.

However, if the number of films is 24, step #247
It is also possible to advance to 0 and add "2" to the counter, or to take the average of both to make the count value 2.5. (However, at this time, it is necessary to be able to count including a decimal point.)

When using DX film, 12-exposure film, 2
0 or 24 exposure film, 36 exposure film,
Step #2: Check whether the film has 72 exposures or not.
455. It is determined in step #2465 and step #2475, and if the number of sheets is 12, 20.24, 36, or 72, step #2460. #24.70. #
2480. In #2485, the contents of the lower 8-bit counter (CNTRI) are set to "B,""2,""1,""3," and "6."
” and sets it in another counter (CNTR3), and proceeds to step #2490.

In step #24.90, the top five and two counters (
The count values of CNTR3) and (CNTR1,) are compared. If the value of the counter (CNTR3) is smaller, it is assumed that a carry has been performed and the upper 8 bits of the counter (CNTR3) are smaller.
CNTR2) plus 1 and its address rO
J is set in each of the output registers, the program proceeds to the write subroutine, writes to the E2PROM, and proceeds to step #25+5 (#2495 to #2510).

When the counter (CNTR3) is larger, the top 8
Proceed to step #2515 without writing any bits,
The contents of this counter (CNTR3) are
Transfer to RI).

The microcontroller (μC) has a counter (CNTRIXCNTR2)
) is determined and processed as follows. That is,
883 or less, address specification variable r (1 to 3” (
#2520→#2525), if it is less than 1666, set address specification variable R1 to “I3” (#2530→#253)
5), when 2499 or less, address specification variable R1 is set to “
23” (#2540→#2545), and when exceeding 2499, address specification variable R1 is set to “33” (#25
40→#2550), respectively, and set the data and address specification variable R1 of the lower 8 bits) to the E2F ROM output register (#2555.#25).
60), proceed to the write subroutine and write this data to E.
Write to 2PROM and return (12565).

Furthermore, the points that required changes compared to the fourth embodiment are that it is no longer necessary to write the total number of releases when the exposure is completed, and that the total number of releases is normalized by the number of films; As shown in Fig. 25, the 20th
Steps #2300 to #2358 in the diagram have been deleted. The latter change can be handled by setting (CNTR2), (CNTR] )≦3332 in step #260Q corresponding to step #2360 in FIG. 21, as shown in FIG.

Furthermore, another modified example will be shown by partially changing the fifth embodiment. In this modified example, when the camera back is opened and the film is removed while the film is loaded (wound around the spool), the number of exposed films is displayed as "0" and E 2F R
I will go to OM to rewrite it.

Flowcharts in that case are shown in FIGS. 27 and 28. FIG. 27 is a modification of the 5ION interrupt routine shown in FIG. 7, in which it is determined whether or not to perform ro-1 writing in place of step #470 in FIG. 7 when no film is loaded. Subroutine for making judgments (#2
700).

This subroutine is shown in FIG.

The microcomputer (μC) sets a flag (FI) indicating the presence or absence of film.
LF) is set #2705),
If it is set, it is assumed that there was a film the last time this flow was executed and that there is no film this time, in other words, the film was removed midway, and the flow of writing "0" is performed below.

First, the flag is reset (#2710). Next, total 1
．． IJ-Z frequency counter (CNTR2, CNTR1
) is 3332 or less (approximately 40,000 times) (#27+5). If it is less than 3332, set variable 1 for the number of film sheets taken to be "0"(#2720), and set this data (NR) and address specification variable R1 to E2PR.
The data and address registers for OM output are set respectively (#2725.#2730), the process proceeds to the write subroutine, and this data rOJ is written (#2735). As a result, even when the film is removed, it will be immediately displayed in the subsequent steps and will be written to the E2PROM immediately, so even if the battery is removed at this time and a new battery is installed, the correct image will be taken. The number of films will be displayed.

In FIG. 28, if the flag is not set in step #2705, or if the predetermined number of rewrites has been exceeded in step #2715, no rewriting is performed and the process returns.

The embodiments and modifications are shown above, and among them, E2PROM
The number of times that the E
This is a limit of 2PROM, and if this number of times changes due to technological improvements, the number of rewrites in the embodiments and modifications may be changed accordingly.

Also, I counted the total number of releases up to 40,000, but it goes without saying that even if it's larger than this, it's still good.

Furthermore, if the release is performed at the same time as winding during initial loading, this number may be counted as the second release number.

Furthermore, in the embodiments and modifications, it goes without saying that the number of times the number of film sheets that have been photographed may be changed is counted.
This method allows more accurate detection of the number of times the number of film shots has been rewritten. To do this, a microcomputer (μC) counts the number of levers, a 2-byte memory (10,000 counts) is provided in the E2Pr (0M) to store this count value every time it is rewritten, and a spare memory is provided. Just do it like this.

[Effects of the Invention] According to the present invention, rewriting is performed only when it is determined that writing of film sensitivity is actually necessary.
The number of rewrites can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a camera according to an embodiment of the present invention, FIG. 2 is a flowchart showing an interrupt routine at the time of battery replacement, and FIG. 3 (I) and FIG.
Flowcharts showing the reading of data from ROM to RAM, FIG. 4 (1) is a flowchart showing the Is○ change subroutine, FIG. 4 (■) is a plan view of the display device, and FIG. 5 is the ISo writing subroutine. 6 is a flowchart showing the subroutine including the same <tsog, FIG. 7 is a flowchart showing the subroutine for preparing for shooting, FIG. 8 is a flowchart showing the control at the time of shirt release, and FIG. 9 is a flowchart showing the subroutine including the same FIG. 10 is a flowchart showing the address change subroutine; FIG. 10 is a flowchart showing the film winding subroutine;
Figure 1 is a flowchart showing the control when the camera back is closed, and Figure 12 is the flowchart 1 of the initial load subroutine.
FIG. 13 is a flowchart showing battery interrupt;
4 is a flowchart corresponding to FIG. 2 showing the first modification, FIG. 15 is a flowchart showing a shirt release routine corresponding to FIG. 8, and FIG. 16 is a flowchart corresponding to FIG. 1O showing the winding subroutine. 17 is a flowchart showing a shirt release routine corresponding to FIG. 15, FIG. 18 is a flowchart of a subroutine for rewriting the number of film sheets taken, and FIGS. 19, 20, and 21 are respectively similar to FIG. 14. , Fig. 15, Fig. 16
The flowcharts corresponding to the figures, FIGS. 22 and 23, are as follows:
Flowcharts corresponding to FIGS. 19 and 11 respectively, FIG. 24 is a flowchart showing a subroutine for reading the number of film sheets, FIG. 25 is a flowchart showing a routine for shirt release, and FIG. 26 is a subroutine for film winding. Flowchart, Figure 27 is a flowchart showing the subroutine of 5ION, Figure 28 is rOJ
3 is a flowchart showing a write determination routine. μC...Microcomputer, E2PROM...Writable/erasable ROM, Sl...Shooting preparation switch, S2...
・Release switch, 5rso...ISO change switch, Su, Sd...up/down switch. Patent applicant: Minolta Camera stock agent: Patent attorney: Mr. Maeda and 2 others No. 67
Figure 8 Figure 7x Figure 12 Figure 13 810 Figure 11 Figure 16 Figure 18

Claims (2)

[Claims] (1) It has a built-in control microcomputer and an E^2PROM whose writing and erasing are electrically controlled by the control microcomputer, and the E^2PROM includes at least a memory that stores the film sensitivity. A film sensitivity change mode setting means sets a film sensitivity change mode, and a film sensitivity setting means sets a film sensitivity to be changed by a predetermined external operation when the film sensitivity change mode is set. means, a rewriting determining means for determining whether or not to rewrite the film sensitivity memory of the E^2PROM using the set film sensitivity, and a film sensitivity change mode when it is determined that rewriting is necessary. and writing means for writing the film sensitivity set by the setting means into the film sensitivity memory area of the E^2PROM when the film sensitivity is set by the setting means.
A camera with a built-in E^2PROM characterized by controlling writing to the 2PROM. (2) The above determination means determines whether the set film sensitivity is
The E^2PROM according to claim 1, which is means for determining that rewriting should be performed only when the film sensitivity is not equal to the film sensitivity currently stored in the E^2PROM.
Built-in camera.