JPS5984228A - Interchangeable lens - Google Patents

Abstract

PURPOSE:To suppress the increase of the number of connection terminals between a camera body and an interchangeable lens by controlling access to the ROM of the interchangeable lens and the transmission of read data by a synchronizing clock from the camera body. CONSTITUTION:The synchronizing clock from the camera side is applied to the interchangeable lens LEC through a terminal JL2 and counted by a counter CO52 through a counter CO50. Then, high-order digit bits based upon the counted value of the counter CO52 are used as an address to access the ROMRO50 and then fixed information corresponding to the interchangeable lens is outputted and supplied to the camera side through AND gates AN61, AN62- controlled by low-order digit bits by the counter CO50 and a terminal JL5. This constitution eliminates the need for an address supply terminal for access to the ROMRO50, so an increase in the number of connection terminals between the camera body and interchangeable lens is suppressed to reduce accidents such as a contact defect.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an apparatus for transmitting various data regarding an interchangeable lens attached to an interchangeable lens camera to the camera.

PRIOR ART Conventionally, there has been a device in which an interchangeable lens is provided with a ROM that fixedly stores various data of the interchangeable lens, an 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. is proposed. This device requires a connector for transmitting address data 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. , R (J M
The present invention is characterized in that the stored data from 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 rest are the circuits on the camera side. (BA) is the camera's power battery, and (MAS) is a manually closed power switch. This power switch (MAS
) is closed, power is supplied from the power supply line (10E) to the microcomputer (hereinafter referred to as μ-com) (MCO) and the oscillator (OSC). Furthermore, when the power switch (MAS) is closed, the power-on reset circuit (FORl) operates, and the p-c
om (MCO) (7) Reset terminal (RE) - A reset signal is sent, and μmcom (MCO) performs a reset operation. Also, a clock pulse from the oscillator (OSC) is sent to the clock terminal (CL) of μmcom (MCO). Furthermore, this clock pulse is used by the exposure time control circuit (1'lc) and the aperture control circuit (APC).
), release circuit (RLC), mirror release circuit (M
RC).

(LMS) is a photometry switch that is closed by the first step of pressing down the release button (not shown);
When S) is closed, the output of the inverter (IN5o) (7) becomes "1-1 i g h", and p -COm(
MCO) to the input terminal (11) of this “kl i g h
When the input terminal (11) of the μmcom (MCO) becomes "'High," the output terminal (01) becomes "'High'" and the inverter (IN
S2) output is set to “LOW” and the transistor (j4T
so) conducts and connects the power line (+V) to the camera side oscillator (OSC) and μmcom (MCO).
In addition to supplying power to circuits other than the buffer (BF)
, the power line (+VF) to the interchangeable lens side circuit (tEC) via the terminals (J'1(t) and (JLI))
Power is supplied via the

The transistor (J4Tao) conducts and the power line (+
■) When power supply starts from the power-on reset circuit (
1'0Rz) operates and the exposure time control circuit (TIC), aperture control circuit (APC), release circuit (RLC), and mirror release circuit (M'RC) are activated from the terminal (PO2).
A reset pulse is sent to reset these circuits.

(LMC) is a photometry circuit, and this photometry output (analog) Bv-Avo (Bv; subject brightness, AVO, open aperture value) is input to the analog input terminal (ANI) for A-D conversion of μmCOm (MCO). In addition, p - c
The input terminal (REV) of om (M CO) is μmco
This is a reference potential input terminal for the D-A converter installed in the MCO.
A reference potential from a constant voltage source provided in the MC is input.

(TIS) is a device that outputs set exposure time data, and this set exposure time data is μmcom (MC
O) is input to the input port (IPl). (AP
S) is a device that outputs data on the set aperture value, and this set aperture value data is input to the input port (IF2) of μmcam (MCO). (FSS) is a device that outputs data of the set film sensitivity, and this set film sensitivity data is input to the input capo (IF5) of the p-com (MCO). (MT)S) is a device that outputs data corresponding to the set exposure calculation mode, and the data from this device is input to the input port (IF) of μmcom (MCO).
5) is input. (DSP) is a display circuit that displays exposure control values and the like, and the display contents are controlled by μmcom (MCO) through a common terminal (COM) and a segment terminal (SEG).

The output terminal (03) of p-com (M CO) is connected to the lens side counter (
CO5G) (CO52) is connected to the reset terminal (RE). This output terminal (03) becomes "High" while reading data from the interchangeable lens, and the reset state of the counters (CO60) and (CO52) is released. p-com (M CO) terminal (
SIC) is a terminal that outputs a clock pulse for synchronization when reading data serially to the terminal (S ID),
(S ID) is the data input in series as mentioned above.
- - Serial input terminal for reading the evening. The terminal (SIC) is connected to the clock input terminal (cr-) of the counter (CO50) via the terminals (JB2) and (JL2), and the terminal (S T, D) is connected to the terminal (JL5).
! The output terminal of the OR circuit (ORso) is connected via (JB5).

FIG. 2 shows an example of a circuit of a serial data reading section provided in the μmcom (MCO) related to the aforementioned terminals (SIC) and (SID). 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 S
IIN), the flip-flop (FFso) is set (FF5oQ in Figure 3), and the AND circuit (AN
70) to the oscillator (OS C) (+)
A clock pulse (DIC) obtained by dividing the pulse within the p-com (M CO) is output from the terminal (SIC) (Fig. 3, 5IC), and this AND circuit (AN70
) clock pulses from a 3-bit binary counter (COao) and an 8-bit shift register (SRs
o) to the clock terminal (CL). The shift register (SR50) 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-1 terminal (CY) of the counter (CO60) becomes “High.
” (Figure 3 CY), and when the 8th clock pulse falls, the output of the AND circuit (A, N72) becomes “H”.
(AN72 in Figure 3). This causes the flip-flop (FF s o) and the counter (
CO60) is set (Fig. 3 FF5o, CY),
Furthermore, a flag for serial data input (S I F L )
is set to I[high” (FIG. 3), and the operation is completed.

Returning to FIG. 1 again, the switch (RLS) is a release switch that is closed in the second step of pressing the release button, and the switch (EXS) is a release switch that is closed when the operation of the exposure control mechanism (not shown) is completed. This switch is closed and opened when the exposure control mechanism is ready for the exposure control operation (charging).

When the exposure control mechanism is fully charged, switch (EXS)
is opened and the output of the inverter (INs6) is “Low”
When the release switch (RLS) is closed, the output of the AND circuit (AN6) becomes "'High"'. The output of this AND circuit (ANao) is μmcom (M
CO) is connected to the interrupt terminal (it) of μmCO
m(MCO) means that this interrupt terminal (it) is "i(ig)l".
”, p-com (MCO) starts an operation for exposure control no matter what operation is being performed.

On the other hand, if the charging of the exposure control mechanism is not completed and the switch (EXS) is closed and the output of the inverter (IN56) is 'High', the release switch (
Even if RLS) is closed, the output of the AND circuit (ANao) does not become 'High' and μmcom (M C
O) does not perform any operation for exposure control.

The output port (OPt) of μmCOm (MCO) outputs exposure time data Tv to the exposure time control circuit (TIC),
The output port (OF2) outputs the aperture stage number data Av-AvO to the aperture control circuit (APC), and the output terminal T-(02) outputs a pulse to start the exposure control operation to the release circuit (RLS). Output and output terminal (04)
outputs a pulse for starting mirror up operation to the mirror release circuit (MRC). In addition, μm cam, (M
The input ports (IPt) to (IF5) of CO), output ports (OPl), and (OF2) are replaced with a common data bus, and data input and output ports are connected to μmcom (MCO).
Small part (TIS), (APS), (FSS).

Data may be transferred between (MDS), (TIC), and (APC) in a time-sharing manner.

Next, in the lens side circuit (LEC), a counter (
COso) and (CO52) are respectively 3-bit binary counters, and the counter (COso) is connected to the terminal (
The counter (CO52) counts the rising edge of the clock pulse from the counter (SIC), and the counter (CO52) counts the falling edge of the carry terminal (CY) of the counter (COso). How the counter (CO50) comes out (hQ).

(ht) + <ha) is input to a decoder (DEso), and this decoder (])Eso) inputs a counter (CO
The signals shown in Table 1 are output according to the data from the so.

10- Table 1 3-bit output (gz) of counter (CO52),
(gz).

(gx) and (go) are input to a decoder (DE52), and the decoder (DE62) outputs the signals shown in Table 2 according to the data from the counter (CO52).

Table 2 Among the outputs of the decoder (DE52), the terminal (gz) is connected to the select terminal (sE) of the data selector (MPso), and the data selector (MP50) is connected to the terminal (
When gz) is "Low", the input data from the input section (.gamma.l) is output, and when "city gh", the input data from the input section (.gamma.2) is output as address data of the ROM (RO50). The upper 5 bits of the input section (door) are connected to ground, and the lower 3 bits are connected to the output terminals (gz), (gt), and (go) of the decoder (1) (E52).

Therefore, as for the address of the ROM (IROs o ), "oooooooo" to "ooooootoo" are sequentially specified while the output of the counter (CO52) is "000" to "too". The input section (γ2) has the output terminals (gz), (gt), (
go) is connected, and the lower 5 bits are a code plate (COD) linked to the focal length setting member (not shown) of the zoom lens.
The data from is input. Therefore, ROM (RO
The address of s o) is the output of the counter (C052).
Between 101” and “111”, “001φ444>φ”
~011 φn” address is specified.Here, φ
indicates that it may be O or 1.

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

13- Table 3 -■4- The address "QQH" (H indicates hexadecimal number) stores the data "'F8H'" for a zoom lens and "'FQH'" for a fixed focus lens. If the camera determines that none of the above data has been read, it will assume that no interchangeable lens is attached and will perform exposure control in aperture metering mode.On the other hand, if any of the above data has been read If it is determined that the exposure is in full open metering mode, 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 maximum aperture value changes as the focal length changes, data of the aperture value at the most open position is stored.

'The data of the maximum aperture value Avmax is stored at the address "02H". Note that, as described above, in the case of a lens whose minimum aperture value changes with a change in focal length, data on the most open side is stored. “'03
H" stores data on the focal length of a fixed focal length lens, and data on the shortest focal length side of a variable focal length lens."04
H" stores data corresponding to the time required for the aperture of the interchangeable lens to start stopping down, stop down to the minimum aperture, and stabilize the aperture (hereinafter referred to as release time lag). Open aperture. The data for the value Avo is
Cancellation of the open aperture element included in the photometric value, (Bv −
Avo) +Avo = Calculation of the number of Bv refinement stages Av - Av.

and aperture value Av are used to determine whether control is possible. 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 is such that camera shake is likely to occur even with a fixed focus lens. 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 calibration aperture is stable even when the aperture is stopped down to the minimum aperture. This is used to perform control so that exposure is started by opening the shutter after the shutter is opened.

Next, if it is a zoom lens, “00100000”
~The address “00111111” has a code board (CO
Focal length data corresponding to the data from D) is stored, and this data is used to determine camera shake warning. “'otoooooo”〜”01011111′
At the address ', data ΔAv of the amount of change in the aperture value corresponding to the data from the code plate (COD) is stored. This data cancels out the elements of this amount of change included in the photometric value, (Bv-(Avo+ΔAv)) - Avo + ΔAv=B
v calculation or calculation for controlling the effective aperture value of the aperture 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. Possible 17- Used for determining whether or not Avo+ΔAv≦Av≦Avmax+ΔAv. For the addresses "01100000" to "01111111"', set the focal length to f and the shortest focal length to 7m.
1n, when the longest focal length is /max, for the value of -fmin,
~30% is '02H', 31%~45% is '0'
4H”, 46% to 60%, “08H”, 61% to 70
% is 'IOH', 71%~80% is '20H',
81%~90% is '40B'', 919fi ~100
%, the data of “80H” is the code board (COD)
This data is used to display, for example, how well the zoom lens is being used. The relationship between the address of the ROM (ROS o) and the stored data and the purpose of use of that data are shown below.

FIG. 4 is a timing chart showing the operation of reading data from the lens. The operation of reading data from the lens 18- of FIG. 1 will be explained below based on the timing chart of FIG. 4. First, μmcom (M
CO) output terminal (03) is 'High'
), the reset of the counter (CO50) (COs2) is released. μ-COm (MCO) clock terminal (
As explained based on FIGS. 2 and 3, eight clock pulses are output from the SIC at each timing of reading one byte of data. In step SO to read the first data, ROM ('ROs o) is at address "o".
Since oooooooo "' is specified, the check data "" FQ H" or "'F8H" is output, and the decoder (DE50) sequentially sets the terminals (eO) to (e7) to "High" as the count of the counter (COso) progresses.
”, open the gates of AND circuits (A, N6g) to (AN61) and connect the output terminal (f
The data from O) to (f7) are sequentially input from the lower bits to the OR circuit (ORso) and the serial input terminal (S
As explained in FIGS. 2 and 3, the data at the input terminal (SII)-\ is output to μ-com( Shift register (SIL) in MCO)
50).

Counter (COso) □＼When the 8th clock pulse is input, the carry-1 terminal (CY
) becomes "'lligh", the next step 81 is entered and a clock pulse is input again, and when this clock pulse rises, the carry-1 terminal (CY) falls to "'Low", and at this fall, the counter starts. (CO52) counts up by one. And IL OM (RO6
0) is designated by the address "00000001" from the input section (γ1) of the data selector (MP50).

The same operation is repeated up to 54 steps, and S4
At the end of the step, the carry terminal (CY) is “Low”
, the output of the counter (CO52) becomes “10”.
1”, and the output of the decoder (DE52) is “1001”.
”.By this, the data selector (MPso)
specifies the address of “00144)φ匈°′” from the input section (γ2) (where the lower 5 bits “φφ” is data from the code board (COD)), and 1 is stored at that address. Data on the set focal length is read into the μ-com (MCO) in the same manner as described above.

In step S6, the address of “010φφ(E)” is specified and the data of ΔAv is specified, and in step S7, the address of “010φφ(E)” is
The address of 11φφφφ is specified and the data of Δf is read into μmcom (MCO).The reading of data for the zoom lens is completed, and p-
The output terminal (03) of com (M CO) becomes L0w'', and the counters (COso) and (CO62) are reset. In addition, in the case of a fixed focus lens, S4
When the step is completed, the output terminal (03) of μmcom (MCO) becomes “Low” and the counter (COso)
.

(CO52) enters the reset state, and reading of data from the lens is completed.

FIG. 5 is a flowchart showing the operation of μmcom (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
Power supply starts from A) to μ21--com (MCO) and the oscillator (O5C) via the power line (+E), and the power-on reset circuit (PORl) starts.
After performing the reset operation, the light metering switch (LMS) in step #2 is closed and the input terminal (il) becomes “H”.
Then, when the input terminal (11) reaches "gh", the output terminal (01) is set to "f-I i g h" in step #3, and the inverter is turned on. (IN52) through the transistor (B
Tso) is made conductive to start supplying power from the power supply line (10V), and at the same time, supplying power to the lens side (LEC) via the buffer (BF) is started.

And input ports (IPl), (IPz), (IF3
).

(IF5) The setting data from register Mo
.

Import it into M1, M2, and M3, and move on to step #8.

In step #8, the output terminal (03) is set to °', High.
h” and counter (COs o), (COs 2
) and set 4H in the K register. Then, in step #10, a serial data input command is issued in line 22-, the data acquisition operation from the lens is started as described above, and the process waits for the completion flag 5IFL to become "1". Then, when flag 5IFL becomes 1'', the fetched data is set in register Mk (initially M4), and it is determined whether register K is ``8H''. If K is not ``8H'', register Add “1゛° to K, move to step #16, determine whether K is “CH”, and if it is not “CH”, #
Returning to step 10, the next data acquisition operation is performed. Repeat the above operation and step 1(
When it is determined that the value has become "8H"', it is determined in step #14 whether the contents of the register M4 are "F8H".

If it is not F 8H, it means that a fixed lens is attached or no lens is attached, so there is no need to read any more data from the lens.
Proceed to step #17. On the other hand, if it is F8H'', it means that a zoom lens is attached, so move to step #15 and continue to import data, and notice that K becomes 'CH' in step #16. If it is determined, the process moves to step #17. Therefore, register M4 has a discrimination code, M5 has Avo, and M6 has A.
vmax.

M7 has fw, Mg has release time lag, M9
f% MA is set to ΔAv, and MB is set to Δf.

In step #17, connect the terminal (03) to “l 1-OWI
+ to reset the counters (COs o) and (CO52), and in step #18, the photometry circuit (L
MC) is subjected to AD conversion, the AD converted data is set in register Mc, and the exposure calculation operation of step #20 is performed.

When the exposure calculation operation is completed, the flag LMF is set to 1, and it is determined whether the flag RLF is 1 in step #22. Then, if the flag RLF is 1, the process goes to step #32, and if not, the process goes to step #23 to display the exposure. The function of flag RLF will be described later.

In step #24, the photometry switch (LMS) is closed and it is determined whether the input terminal (il) is "ts i gh". If (11) is "0igh", return to step #2, and proceed to step #3. Repeat the action from step. Meanwhile, #
When it is determined that (il) is “Low” in step #24, the output terminal (01) is set to L in step #25.
ow” to stop the power supply from the power line (10) and the power supply to the lens side (LEC).Then, the display will be blank and nothing will be displayed, and the photometry flag L will be turned off.
Set MF to O, return to step #2, and wait for the light metering switch (LMS) to be closed again.

When the exposure control mechanism is fully charged, the switch (EXS
) is open and the release switch (RLS) is closed, the output of the AND circuit (AN60) becomes "'I-(
and the interrupt terminal (it) becomes I+ +-
It becomes 4i gh++. Then p-com (MCO)
No matter which step is being performed, it immediately moves to step #3° and sets the release flag RLF to 1. In step #31, an interrupt is generated while reading serial data. As a countermeasure when the operation is performed, set the output terminal (03) to "'Low",
At step #32, it is determined whether the flag LMF25- is 1 or not. And the flag LMF is 1
Otherwise, the exposure control data calculation has not been completed.
The process moves to the flow of data acquisition starting from #4 to calculate the exposure control value, and in step #22, in this case, since the release flag RL F is set to 1, the process moves to step #33. return.

If the flag LMF is 1 in step #32, #
Proceed to step 33 and write the exposure time data for control.
V to the output port (Ul't) or the exposure time control circuit (T, IC), the number of warping stages data for control A
v - A v O is output from the output port (OP2) to the aperture control circuit (APC), and a pulse for release is output from the terminal (02) to the release circuit (ItLC) of the exposure control mechanism.

In step #36, the controller waits for a time r1 corresponding to the release time lag data taken into the register M8, and then outputs the output from the output terminal (04) to the mirror up release circuit (M
RC), the exposure control operation is completed, the switch (EXS) 26- is closed, and the input terminal (12) becomes "High". Then, when the input terminal (12) becomes "High", the flag RL F is set to O, and the process moves to step #24, and if the photometry switch (LMS) is closed, the operation from #3 is repeated. If it is not closed, the power supply is stopped, the display is turned off, the flag LMF is set to 0, and the light metering switch (LMS) is waited for to be closed.

FIG. 6 is a time chart of the sprouting control operation.

p-com (MCO) (7) When a release pulse is output from the output terminal (02), the aperture is narrowed down from opening, and when a pulse is output from the output terminal (02), Tt
After that, a pulse is output from the output terminal (04) and the mirror-up operation starts. When the mirror-up operation is completed, the shutter front curtain is unlatched by the mechanical structure and the shutter front curtain starts running. After T4 (T4 is the exposure time control circuit )
This corresponds to the time counted by 2-'I'v. ) The rear shutter curtain starts running.

Here, the time required to raise the mirror is '1''2, and the terminal (
02), the pulse is output, the aperture is narrowed down to the minimum aperture, and the time it takes for the aperture aperture to become stable is TI+T,
If it is +, then T l + T32 If it is T I + T 2, the leading curtain will start leading and the screen frame (1])
- At time I when the exposure of \ starts, the aperture aperture is definitely stable and exposure unevenness does not occur. Since the width of T+ 173 varies from lens to lens, if you change Tt according to the release time lag data, you can reliably adjust the exposure due to the difference in aperture speed no matter what kind of interchangeable lens is attached. Unevenness can be prevented.

The above is a detailed explanation of this invention. The above ROM (
In addition to this, it is conceivable to store the following as fixed data in the RO 50).

The data of the open photometry error is stored at the address "oooootot", and based on this data, the error component included in the photometry output is removed. The "ooooootto" 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. “
The address '00000111°' 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 ΔI'l (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, there are K and ΔIR in addition to those explained in the embodiment as things that change depending on the focal length, so K is "10000000" to "1001111".
1'"=29-, ΔIlt is "10100000"~"1
0111111'" 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).

This invention counts clock pulses from the camera, specifies the address of the ROM based on this count value, and serially transmits stored data from the ROM to the camera one bit at a time based on the count value. This eliminates the need to transmit address data between the camera and 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 count value of clock pulses, the circuit structure is simple.

[Brief explanation of drawings]

Figure 1 shows the block diagram of the entire camera system to which this invention is applied, and Figure 2 shows the μmcom (MCO)3 of Figure 1.
0- is a circuit diagram showing the specific circuit configuration of the serial data input section, Fig. 3 is a time chart showing the operation of Fig. 2, and Fig. 4 is a circuit diagram showing the operation of Fig. 1. A time chart showing the operation, Figure 5 is the μmc of Figure 1.
om(MCO) operation, and FIG. 6 is a time chart of exposure control operation. Clock pulse input means...JL2, counter...
ω50゜CO52, address data output means...l)
E s 2 , COD , MP sζRUM =・RO
50, Memory data output means...DEs O, AN61
, AN62゜AN63 , /'J'J64 , AN6
s, AN66, AN67, AN68. ORs o
, J.Ls. Applicant Minolta Camera Co., Ltd. 31-209-

Claims (1)

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