JPS62275232A - Interchangeable lens - Google Patents

Abstract

PURPOSE:To decrease the number of electric contacts between a camera and an interchangeable lens by specifying an address of a ROM on the basis of the counted value of clock pulses from the camera and also transmitting stored data from the ROM to the camera in series, bit by bit, on the basis of the counted value. CONSTITUTION:Starting data is read in and then '00000000' is specified as the address of the ROM RO50, so check data 'FOH' or 'F8H' is outputted and a decoder DE50, holds terminals e0-e7 at 'Hight' in order as a counter CO50 counts up to open the gates of AND circuits AN68-AN61. Then, data from output terminals f0-f7 of the ROM RO5 are outputted to the series input terminal SID of a microcomputer MCO from low-order bits through an OR circuit OR50 and terminals JL5 and JB5 in order, and the data to the input terminal SID are read in a shift register SR50 in the microcomputer MCO. When the 8th clock pulse is inputted, and '00000001' is specified as the address of the ROM RO50.

Description

[Detailed description of the invention] 3. Detailed description of the invention! BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for transmitting various data regarding an interchangeable lens attached to an interchangeable lens camera to the camera.
- Prior art Conventionally, an interchangeable lens is provided with a ROM that fixedly stores various data of the interchangeable lens, the address of the ROM is designated based on address data from the camera, and the stored data from the ROM is serially transmitted to the camera. A device has been proposed. This device requires an address data transfer connector between the interchangeable lens and the camera. Incidentally, it is desirable to have as few electrical connection terminals between the camera and the interchangeable lens as possible in terms of reliability and cost.

Purpose The purpose of this invention is to propose an interchangeable lens that has as few electrical contacts as possible with a camera.

Summary This invention counts clock pulses sent from the camera to the interchangeable lens on the interchangeable lens side in order to synchronize the operations between the camera and the interchangeable lens, and based on the contents of the upper digits of this count value, The interchangeable lens itself specifies the address of the ROM, and data stored in the ROM is serially transmitted bit by bit to the camera based on changes in the lower digits of the count value.

Embodiment FIG. 1 is a block diagram showing an interchangeable lens camera system to which the present invention is applied.
EC) is the circuit on the lens side, and the remaining circuits are on the camera side. (BA) is the camera's power battery, and (MAS) is a manually closed power switch.

When this power switch (MAS) is closed, power is supplied from the power line (+E) to a microcomputer (hereinafter referred to as microcomputer) (MCO) and an oscillator (OSC). Furthermore, when the power switch (MAS) is closed, the Zwar-on reset circuit (PORl) operates, and a reset signal is sent from the terminal (POl) to the reset terminal (RE) of the microcomputer (MCO). M.C.O.
) A beam cent action is performed. In addition, the oscillator (OSC
) is the clock from the microcomputer (MCO) (7)
Sent to I lock terminal (CL). Furthermore, this clock pulse is also supplied to an exposure time control circuit (TIC), an aperture control circuit (APC), a release circuit (RLC), and a mirror release circuit (MRC).

(LMS) is a photometry switch that is closed when the release button (not shown) is pressed down in the first step.
When MS) is closed, the output of the inverter (IN5o) becomes "High", and this "High" signal is transmitted to the input terminal (11) of the microcomputer (MCO'). The input terminal (11) of MICO y (MCO) is “High”.
”, set the output terminal (0□) to “High” and
The output of the inverter (IN5□) is set to LOW'', the transistor (BT5o) is made conductive, and the power supply line (+V) is turned on.
From the camera side oscillator (OSC), microcontroller (MCO)
In addition to supplying power to circuits other than the buffer (BF)
, terminals (JI31), (JL, ), power is supplied to the circuit (LEC) on the interchangeable lens side via the power supply line (+VF).

The transistor (BT5o) becomes conductive and the power supply line (+V
) starts supplying power, the power-on reset circuit (
POR2) operates, and the exposure time control circuit (TIC), aperture control circuit (APC), release circuit (RLC), mirror release circuit (MRC) heli-set pulses are sent from the terminal (PO2) to these circuits. is reset.

(LMC) is a photometry circuit, and this photometry output (analog) By -Avo (Bv; subject brightness, Avo
; open aperture value) is input to the analog input terminal (ANI) for A-D conversion of the microcomputer (MCO). moreover,
The input terminal (REV) of the microcomputer (MCO) is a reference potential input terminal for the D-A converter provided in the microcomputer (MCO).
A reference potential from a constant voltage source provided within the IMC is input.

(TIS) is a device that outputs the data of the set exposure time, and this set exposure time data is sent to the microcomputer (MCO).
is input to the input beat (IPl) of.

(APS) is a device that outputs data of the set aperture value, and this set aperture value data is input to the input (IF5) of the microcomputer (MCO). (FSS) is a device that outputs data on the set film sensitivity, and this set film sensitivity data is input to the input heat (IF3) of the microcomputer (MCO).

(MDS) is a device that outputs data corresponding to the set exposure calculation mode, and data from this device is input to the input port (IF4) of the microcomputer (MCO).

(DSP) is a display circuit for displaying exposure control values, etc., and the display contents are controlled by a common terminal (COM) and a segment terminal (SEG) from a microcomputer (MCO).

The output terminal (03) of the microcomputer (MCO) is the terminal (JL3
), (JL3) to the lens side counter (CO5o
) (CO5□) Connected to the glue cent terminal (RE).

This output terminal (03) becomes "H4gh" while reading data from the interchangeable lens, and the counter (C05o), (
C05□) has been released from the reset state. Microcomputer (
The terminal (SIC) of the MCO) is the terminal that outputs the clock signal for synchronization when reading data serially to the terminal (SID), and (SID) is the terminal that outputs the clock signal that is used to read data serially to the terminal (SID). This is a serial input terminal for reading.

And the terminal (SIC) is the terminal (-JB2), (JL2
) of the counter (CO5o) via the clock input terminal (
CL), and the terminal (SID) is connected to the terminal (JLs).
) and (JB5) are connected to the output terminal of an OR circuit (OR5o).゛Figure 2 shows the aforementioned terminal (S
A circuit example of a serial data reading section provided in a microcomputer (MCO) related to IC) and (SID) is shown. FIG. 3 is a time chart showing the operation of the circuit shown in FIG. 2.

In FIG. 2, the serial data read instruction (SIIN)
(Fig. 3, 5IIN), there are 7 lip-flops (F
F5o) is set (FF50Q in Figure 3)% The AND circuit (AN7o) outputs clock pulses (DIC), which is the frequency of the oscillator (OSC) clock pulse divided within the microcomputer (MCO), from the terminal (SIC). (Fig. 3, 5IC), the clock pulse from this AND circuit (AN, .) is output from a 3-pin binary counter (C
O6o) and the clock terminal (CL) of the 8-pit shift register (SR5o). The shift register (SR5o) takes in data from the terminal (SID) every time the clock to the clock terminal (CL) falls.

Then, when the 8th clock pulse rises, the carry terminal (cy) of the counter (C06°) becomes “High”.
(Figure 3 CY), and when the 8th clock pulse ξ falls, the output of the AND circuit (AN, □) becomes “Hi”.
gh” (Fig. 3 AN7□). This causes the flip-flop (FF5o) and counter (C06
o) is reset (FF5o1CY in Figure 3), and the serial data input flag (SIFL) is set to “High”.
” (FIG. 3, 5IFL) to complete the operation.

Returning to FIG. 1 again, the switch (RLS) is a release switch that is closed in the second step of pressing down on the release button, and the switch (EXS) is a release switch that is closed by the second step of pressing the release button.
This switch is closed when the operation of the exposure control mechanism (not shown) is completed, and is opened when the preparation (charging) of the exposure control mechanism is completed. When the charging of the exposure control mechanism is completed, the switch (EXs) is opened and the inverter (INss)
When the output is “Low”, press the release switch (RLS).
) is closed, the output of the AND circuit (AN6o) is "
becomes “High”.

The output of the AND circuit (AN6o) is output from the microcomputer (MCO).
) is connected to the interrupt terminal (it) of the microcontroller (M
When this interrupt terminal (it) rises to "High", the microcomputer (MCO) starts the exposure control operation no matter what operation it is performing. On the other hand, the charging of the exposure control mechanism is not completed and the switch (EXS) is closed, and the output of the inverter (IN56) becomes "High".
”, even if the release switch (RLS) is closed, the output of the AND circuit (AN6o) will be “High”.
”, and the microcomputer (MCO) does not perform any operations for exposure control.

The output beat (OPl) of the microcomputer (MCO) outputs exposure time data Tv to the exposure time control circuit (TIC), and the output dart (OR2) outputs aperture depth stage number data Av-Avo to the aperture control circuit (APC). and output terminal (0□)
outputs a nose pulse for starting an exposure control operation to the release circuit (RLS), and an output terminal (o4) outputs a nose pulse for starting a mirror-up operation to the mirror release circuit (MRC). In addition, the input Pete (IP) of the microcomputer (MCO)
l) ~ (IP4), output port (OR engineering), (OR2)
is replaced with a common data bus, and a microcontroller (MCO)
and data entry and exit (TIS), (APS), (FSS)
), (MDS), (TIC), and (APC) may be time-divisionally transferred.

Next, in the lens side circuit (LEC), a counter (
CO5o) and (CO5□) are each 3-pinto binary -
The counter (CO5o) is a terminal (SIC
), and the counter (CO5□) counts the falling edge of the carry terminal (cy) of the counter (CO5o). counter(
CO5o) 3-bit output (h2), (hl), (h
o) is input to a decoder (DE5o), and this decoder (DE5o) outputs the signals shown in Table 1 according to the data from the counter (CO5o).

Table 1 Output of 3 pits of counter (CO5□) (h5), (h
4) and (h3) are input to the decoder (DE5□), and the decoder (DE52) outputs the signals shown in Table 2 according to the data from the counter (Co5□).

Table 2 Among the outputs of the decoder (DE5□), the terminal (g3) is connected to the select terminal (SE) of the data selector (MP5o), and the delta selector (MP5o) is connected to the terminal (
When g3) is "Low", the input data from the input section (.gamma.1) is output, and when it is "High", the input data from the input section (.gamma.2) is output as address data of the ROM (ROso). The upper five bits of the input section (γ1) are connected to ground, and the lower three pits are connected to the output terminals (g2), (gl), (g, ) of the decoder (DE5°). Therefore, the address of the ROM (RO5o) is "when the output of the counter (C05°) is between "OOO" and "100".
``oooooooooo'' to ``ooooooioo'' are sequentially specified.

The input section (γ2) has a decoder (DE52) at the upper three pits.
) are connected to the output terminals (g2), (gl), and (go), and the lower 5 bits are input with data from a code board (COD) linked to the focal length setting member (not shown) of the zoom lens. . Therefore, the address of the ROM (R05o) is the output of the counter (CO5°) "101" - "11"
Between 1" is "001 chain φφφφ" to "011121φφ
The address of φφ'' is specified. Here, φ indicates that it may be O or 1.

Next, data stored in each address of the ROM (RO5o) will be explained with reference to Table 3.

Table 3 The address "OOH" (H indicates a hexadecimal number) stores the data "F8H" for a zoom lens and "FOH" for a fixed focus lens, and both of these data are stored on the camera side. If it is determined that the lens has not been read, it is determined that no interchangeable lens is attached, and exposure control is performed in aperture metering mode. On the other hand, if it is determined that any of the above data has been read, exposure control is performed in open metering mode.

At the address "OIH", data of the open aperture value Avo is stored. Note that in the case of a lens whose aperture value changes as the focal length changes, data of the aperture value at the most open side is stored.

At the address "02H", data of the maximum aperture value Avmax is stored. Note that, as described above, in the case of a lens whose minimum aperture value changes as the focal length changes, data on the most open side is stored. "03H" stores data on the focal length of a fixed focal length lens, and data on the shortest focal length side if a variable focal length lens is stored. "04H" stores data corresponding to the time required for the aperture of the interchangeable lens to start stopping down to the minimum aperture and for the aperture to stabilize (hereinafter referred to as release time lag). The data of the open aperture value Avo is obtained by canceling the element of the open aperture value included in the photometric value, (By −Avo
) + Avo = By calculation of the number of narrowing stages Ay - Av.

and is used to determine whether the aperture value Av can be controlled. The maximum aperture value Avmax is used to determine whether the aperture value Av can be controlled. Focal length data is used to determine whether the exposure time of a fixed focus lens is such that camera shake is likely to occur. The details of the release time lag data will be described later, but the time difference between the release of the exposure control mechanism and the release of the mirror up mechanism is determined according to this data, and the aperture aperture is stabilized even when the aperture is stopped down to the minimum aperture. This is used to perform control so that exposure is later started by opening the shutter.

Next, if it is a zoom lens, “0O100O00”~”
The address 00111111'' has a code board (COD).
') is stored, and this data is used to determine camera shake warnings. Data ΔAv of the amount of change in the aperture value corresponding to the data from the code board (COD) is stored in addresses from "old oooooo" to "'01011111".

This data cancels out the elements of this amount of change included in the photometric value, (Bv-(Avo+ΔAv))+AVO+ΔAv=B
Calculation of y or calculation for controlling the effective aperture value of the aperture on the lens side to the aperture value Av set on the camera side, Av-(Avo+ΔAv) and controlling the effective aperture value to the aperture value Av. It is used to determine whether Avo+ΔAv<Av≦Avmax+ΔAv. Addresses from “01100000” to “01111111” have the setting focal length f and the shortest focal length fmi.
n, when the longest focal length is fmax x, /max
-/min value: 0% to 15% is "OIH", 16% to
102H" for 30 inches, "04H" for 31 inches to 45%
, "08H" for 46-60 inches, "IOH" for 61%-70 inches, "20H" for 71-80%, 81%-
“40H” for 90 inches, “80H” for 91 inches to 100 inches
'' data is stored in accordance with data from a code board (COD), and this data is used, for example, to display how much power a zoom lens is being used.

The above is the relationship between the address of the ROM (ROso) and the stored data, and the purpose of using that data.

FIG. 4 is a timing chart showing the operation of reading data from the lens. The reading of data from the lens shown in FIG. 1 and its operation will be explained below based on the timing chart shown in FIG. 4. First, the output terminal (03) of the microcomputer (MCO) becomes "High" and the counter (C05O)
The reset of (COs□) is released. Microcomputer (
2 and 3 from the clock terminal (src) of MCO).
As explained based on the figure, eight clock pulses are output every time one byte of data is read.

Step S of reading the first data. Then ROM (R
Os o ) has address “oooooooo” specified, so check data “FOH” or “F8H”
is output, and the decoder (DE5o) outputs the counter (CO5
As the count of o) progresses, terminals (e□) to (C7)
are set to "High" in sequence, and the AND circuit (AN68) ~
Open the gate of (AN6□) and input the data from the output terminals (fo) to (f7) of ROM (ROso) sequentially from the lower bit to the OR circuit (OR5o), terminal (JL5), and (JB
5) The series input terminal (SI) of the microcomputer (Mco)
D), and as explained in Figures 2 and 3, when the falling edge of the clock pulse, which is the same as the clock pulse from the terminal (SIC), is 9, the data to the input terminal (SID) is output to the microcomputer. (MCO) is read into the shift register (SR5o).

When the 8th Chrono Kuzurus is input to the counter (CO5o), the carry one terminal (CY
) is not "High", the clock moves to the next step 81 and the clock pulse is input again, and when this clock pulse rises, the carry terminal (CY) falls to "low", and at this fall, the counter ( CO52) counts up by one. And ROM (ROso) is “oo” from input part (γ1) of data selector (MP5o).
The address of "oooo old" is specified.

The same operation is repeated until the 84th step, and when the carry terminal (cy) falls to "Low" at the end of the S4 step, the output of the counter (C05°) becomes "101" and the output of the decoder (DE5°) becomes "101". As a result, the data selector (MP5o) receives the input from the input section (γ2) as "001121φφφnail" (here, the lower 5 bits !■121ilφ) is the code board (COD).
The data on the set focal length stored at that address is read by the microcomputer (MCO) in the same manner as described above. In step S6, the address of "010φL3φexcellentφ" is specified and ΔA7
The data of 011 and φφφφ″ are specified in the S7 steno, and the data of Δf is sent to the microcomputer (MCO).
is loaded into. The reading of data for the zoom lens is now complete, and the microcomputer (MCO) output terminal (
03) becomes “Low”, the counter (CO5o),
(C05□) becomes a reset state. In addition, in the case of a fixed focus lens, when the S4 step is completed, the microcomputer (MC)
The output terminal (03) of O) becomes “Low” and the counter (
When CO5o) and (CO5□) are in the reset state, data reading from the lens is completed.

FIG. 5 is a flowchart showing the operation of the microcomputer (MCO). The overall operation of FIG. 1 will be described below based on the flowchart of FIG. 5.

When the main switch (MAS) is closed, the power supply battery (B
A) to the microcomputer (MC) via the power line (+E).
As the power supply to O) and oscillator (O3C) starts,
After the microcontroller (MCO) performs a reset operation using the signal from the ZW-on-reset circuit (FOR),
The process moves to step +2, where the photometric switch (LMS) is closed and the operation waits for the input terminal (1□) to become "High". Then, the input terminal (11) is set to “High”.
”, the output terminal (0□) is set to “Hi” in +3 steps.
gh", conducts the transistor (BT5o) via the inverter (IN5□) to start feeding power from the power supply line (+V), and also starts feeding power to the lens side (LEC) via the buffer (BF). Then, input capo) (IP, ), (IP2), (IP3), (
The setting data from IP4) is sequentially transferred to register M. , Ml,
The data is taken into M2 and M3, and the process moves to step 4=8.

At step +8, the output terminal (03) is set to “High”
to release the reset state of the counters (CO5o) and (CO5□) and set 4H in the K register. And +
In step 10, a serial data input command is executed to start the operation of taking in data from the lens as described above, and wait for the completion flag SH'L to become "1". Then, when flag 5IFL becomes 1#, the imported data is set in register Mk (initially M4), and register K becomes “
8H". If K is not "8H", add "1" to register K, move to step 4p16, and determine whether K is "CH". If it is not "CH", the process returns to step +10 and performs the next data fetching operation. The above operation is repeated, and when it is determined at step +13 that K has become "8H", it is determined at step +14 whether the contents of register M4 are "F8H". And “F8H”
Otherwise, it means that either a fixed lens is attached or no lens is attached, so there is no need to read any more data from the lens, and the process moves to step +17. On the other hand, if it is "@F8H", it means that a zoom lens is attached, so it moves to step +15 and continues to import data, and at step +16 it is determined that K has become "CH". +17 when done
Move on to the next step. Therefore, register M4 has a discrimination code, M5 has Avo, M6 has Avmax,
M7 has release time lag, fviSMB has
M is set to f, MA is set to ΔAv, and MB is set to Δf.

At step +17, the terminal (03) is set to "Low" to reset the counters (C05o) and (CO5□), and at step +18, the output of the photometry circuit (LMC) is converted from AD to AD. The data is stored in register Me.
, and performs an exposure calculation operation of +20 steps.

When the exposure calculation operation is completed, set the flag ■ to 1 and set it to +22.
In step , it is determined whether the flag RLF is 1 or not. Then, if the flag RLF is 1, the step is +32,
If it is not 1, the process moves to step 4=23 and exposure display is performed. The function of flag RLF will be described later.

At step +24, the photometry switch (LMS) is closed and it is determined whether the input terminal (il) is "High". If (11) is "High", the process returns to step +2 and the operation from step +3 is performed. Repeat. On the other hand, if it is determined that (11) is "Low" at the step ≠U, the output terminal (0□) is set "Low" at the step +25.
power supply from the power line (+V) and the lens side (L
EC). Then, the display is blanked, the photometry flag LMF is set to O, and the process returns to step #1-2 to wait for the photometry switch (LMS) to be closed again.

When the exposure control mechanism is fully charged, the switch (EXS
) is open, press the release switch (RLS)
is closed, the output of the AND circuit (AN6o) becomes “Hi”
gh” and the interrupt pin (it) becomes High'.Then, the microcomputer (MCO) immediately shifts to the +30 step no matter which step it is operating and sets 1 to the 7-lag RLF for release. At step +31, the output terminal (03) is set to "Low" as a countermeasure in case an interrupt operation is performed while reading serial data, and at step +32, it is checked whether the flag LMF is 1 or not. If the flag LMF is not 1, the calculation of the exposure control data has not been completed, so the process moves to the flow of data import calculation starting from +4 to calculate the exposure control value, and in step +22, the calculation of the exposure control data is not completed. In this case, since the release flag RLF is 1, the process returns to step +33.

If flag LMF is 1 at step +32, immediately +
Proceeding to step 33, control exposure time data Tv
from the output beat (OPl) to the exposure time control circuit (TIC)
), the aperture stage number data Av -Avo for control is output from the output beat (0P2) to the aperture control circuit (APC), and from the terminal (0□) to the exposure control mechanism's IJ Output Noculus.

At step +36, it waits for a time T1 corresponding to the release time lag data taken into register M8,
From the output terminal (04) to the mirror up release circuit (MR
The release and F pulses are output to C), the exposure control operation is completed, the switch (EXS) is closed, and the input terminal (1
2) wait for it to become "High".

Then, when the input terminal (12) becomes "High", the flag RLF is set to O, and the process moves to step +24. If the light metering switch (LMS) is closed, the operation from ≠3 is repeated, and the switch is closed. If not, stop the power supply, turn off the display, set the flag LMF to 0, and turn the light metering switch (L
MS ) is closed.

FIG. 6 is a time chart of exposure control operation.

Release from the output terminal (0□) of the microcomputer (MCO)
When the pulse is output, the aperture is narrowed down from the open position, and the pulse is output from the output terminal (0□), and after T1,
A pulse is output from the output terminal (04) and the mirror-up operation starts. Then, when the mirror-up operation is completed, the shutter front curtain is mechanically unlatched and the glossy front curtain starts running, and after T4 (T4 is the exposure time control (This corresponds to the time of 2-Tv counted by the circuit (TIC).) The trailing curtain of the shutter starts running.

Here, the time required for the mirror amplifier is T2, terminal (02
), the time it takes for the aperture to close to the minimum aperture and for the aperture to stabilize is T1-←T3.If we set T1 +T3×T1 +T2, the leading curtain will start. Therefore, at the time τ when exposure to the screen frame (D) starts, the aperture aperture is reliably stable and uneven exposure does not occur. And T for each lens
Since the width of 1+T3 varies, by changing T1 according to the release time lag data, exposure unevenness due to differences in aperture speed can be reliably prevented no matter what kind of interchangeable lens is attached.

The above is a detailed explanation of this invention. The above ROM (
In addition to this, it is conceivable that the following items may be stored in the ROso) as fixed data. "000001.01"
Data on open photometry error is stored at the address , and error components included in the photometry output are removed based on this data. The "ooooooiio" address indicates whether the lens can be automatically focused by a motor built into the lens in response to a command from the camera, if the lens can be automatically focused by the camera's motor, or if the focus can only be adjusted manually. Data for determining whether it is a lens or a lens for which focus detection itself is impossible based on object light passing through the lens is stored. "00000111"
The address contains a conversion coefficient K (N=K・ΔL) is stored.

Furthermore, data indicating which direction the camera motor should be rotated to extend the lens is stored at the address "00001000." ”00001001
” stores data on the amount of deviation ΔIR of the focus position from visible light when camera focus detection is performed based on infrared light.

On the other hand, in the case of a zoom lens, in addition to what was explained in the example as changing depending on the focal length, there are K and ΔIR, so K is "10000000" to "1001111".
1" address, ΔIR is "10100000"~"
10111111'' and save it to the code board (C
What is necessary is to output K and ΔIR corresponding to the set focal length according to the data from OD).

Effects This invention counts chronographs from the camera, specifies the address of the ROM based on this count value, and serially transmits stored data from the ROM pin by pin to the camera based on the count value. This eliminates the need to transmit address data from the camera to the interchangeable lens, reducing the number of electrical contacts between the camera and the interchangeable lens, improving reliability and reducing costs.・Since address designation and storage data transfer are performed based on the pulse count value, the circuit configuration is simple.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the entire camera system to which the present invention is applied, Fig. 2 is a circuit diagram showing the specific circuit configuration of the serial data input section of the microcomputer (MCO) shown in Fig. 1, and Fig. 3 is the circuit diagram shown in Fig. 2. FIG. 4 is a time chart showing the operation of data transfer from the interchangeable lens to the camera in FIG.
) is a Solow chart showing the operation, and FIG. 6 is a time chart of the exposure control operation.

Claims (1)

[Claims] 1. A means for inputting clock pulses from a camera, a counter for counting clock pulses from this clock pulse input means, a means for outputting address data based on the output of the upper bits of this counter, and this address data output. An exchange characterized by comprising: a ROM whose address is designated by address data from the means; and means for sequentially outputting stored data from the ROM bit by bit to the camera based on the output of lower bits of the counter. lens.