JPH0776806B2 - Camera lens position detector - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens position detecting device for electrically detecting a change in focal length of a zoom lens due to zoom operation.

[Prior Art] In a camera equipped with a zoom lens, it is necessary to know the F number of the shooting lens at the time of shooting for exposure calculation, and in a camera equipped with an electric zoom device, it is also necessary to control zooming. It is necessary to know what the focal length of the lens is set to.

Therefore, conventionally, a code plate is attached to a cam barrel for driving a zoom lens so that the cam barrel rotates integrally with the cam barrel, and a brush slidingly contacting the code plate is provided on the body side, which is detected by the conduction state of the brush. The position of the lens is determined from the zoom code.

[Problems to be Solved by the Invention] By the way, the above zoom cord has a conduction relationship between a ground brush that is in constant contact with a conduction pattern of a code plate and a code brush that switches between a conduction portion and a non-conduction portion of the code plate. Detected by.

However, since the brush and the cord plate have a mechanical structure, there is a possibility that a contact failure between the cord brush and the cord plate may occur due to an external factor such as vibration.

In the drive range of the photographic lens, a stop prohibition area may be set, for example, between a storage position and a position where photography can be performed. With the configuration that the passage of this stop prohibition area is detected by the change of the brush from ON to OFF, the terminal which is originally ON is detected as OFF due to the poor contact between the brush and the code plate, and the zoom motor is detected in the stop prohibition area. It may stop.

[Object of the Invention] The present invention has been made in view of the above problems,
An object of the present invention is to provide a lens position detection device for a camera, in which the zoom lens does not stop in the stop prohibition area even when contact failure between the brush and the code plate occurs.

[Means for Solving the Problems] In the lens position detecting device according to the present invention, the code plate is configured to use the change from the OFF state to the ON state of a predetermined terminal in detecting the passage of the stop prohibition region.

With such a configuration, since the ON state is not detected in the area where the terminal is OFF, even if there is a contact failure between the brush and the cord plate, the stop at the stop prohibition position can be avoided.

[Embodiment] Hereinafter, the present invention will be described with reference to the drawings.

1 to 24 show an embodiment of the present invention.

First, the appearance of a camera equipped with the electric zoom device according to this embodiment will be described with reference to FIGS.

In FIG. 1, 1 is a camera body, and 2 and 3 are zoom lens barrels. On the front side of the camera body 1, the second
As shown in the figure, a distance measuring unit 4, a finder window 5, a flash 6, a CdS as a light receiving element, and a self-timer lamp 7 are provided. On the back side of the camera body 1, a back cover 8, an LCD display 9, a mode button are provided. A, a mode button B, a clear button C, a zoom lever 10, a green lamp D, a red lamp E, and a back lid opening lever 11 are provided, and the back lid opening lever 11 is moved in the arrow direction from its ascending stop position to its descending stop position. When it is operated to, the back cover 8 is opened. When the back lid 8 is open, the back lid opening lever 11 is at the lowering stop position, and when the back lid 8 is closed, the back lid opening lever 11 moves up and stops.

The back cover 8 has a date display section 12 and a date switching button 13
Is provided. A rewind button (not shown) is provided on the bottom of the camera body 1.

As shown in FIG. 1, a power lever 14, a shutter button 15, and a macro button 16 are provided on the top of the camera body 1. The power lever 14 is slid between the power ON position and the power OFF position.

Move the zoom lever 10 between the wide side and the tele side with the arrows r1 and r2.
Operated in the direction. The zoom lever 10 is also used for changing the manual shutter time or the interval time, which will be described later. This will be described collectively when the functions of the mode button A, the mode button B, and the clear button C are described. And

Next, the circuit configuration of the camera described above will be described with reference to FIG.

The center of this control circuit is the main CPU, and a sub CPU that performs shutter-related processing in parallel with this is connected via a drive IC.

The main CPU performs the following control based on the input from the information input means such as a switch.

(1) The zoom motor and the film motor are controlled via each motor drive circuit.

(2) The lighting and blinking of the green lamp D for displaying the distance-related display, the red lamp E for displaying the flash-related display, and the self-timer lamp 7 for displaying the self-timer are controlled.

(3) The display on the LCD display 9 is controlled.

(4) Control the charging of the strobe circuit.

And, as the information input means for the main CPU, there are the following.

(1) Lock switch LOCK that turns on when the power lever 14 is in the power off position.

(2) Metering switch SWS that is turned on by pressing the shutter button 15 one step.

(3) Relays switch SWR that turns on when the shutter button 15 is pressed in two steps.

(4) Self-back macro switch MCRO that turns on when macro button 16 is pressed.

(5) Turned on by tilting the zoom lever 10 to the tele side r2
Tele switch TELE for zoom.

(6) By tilting the zoom lever 10 to the wide side r1
Wide switch WIDE for zoom to be turned on.

(7) Speed switch ZMHL that turns ON when the tilt angle of the zoom lever 10 is small, and turns OFF when the tilt angle is large.

(8) Self-back mode A switch MDA, mode B switch MDB, clear switch MDC that is turned on by pressing each mode button A, B, clear button C.

(9) DX contact that reads the DX code printed on the film cartridge.

(10) Zoom code input means ZC0, ZC1, ZC2 described later.

(11) When the back cover release lever 11 is pressed down, it turns off and the back cover 8
Back cover switch BACK that turns on when is closed and the lever is raised to the locked position.

(12) A self-back rewind switch REW that turns on when the rewind button is pressed.

(13) Film feed detection switch that detects the presence or absence of film feed.

The three zoom-related switches TELE, WIDE and ZMHL are configured to be turned ON / OFF by one zoom lever, and the arrangement of the contacts is as shown in FIG. With these combinations, five states can be input to the main CPU, and the data is used in zoom operation or mode setting. For example, when zooming,
As shown in the figure, the main information is the information about the forward / reverse rotation of the zoom motor and the switching between high speed and low speed for each rotation.
Input to CPU.

On the other hand, the sub CPU is an infrared LED via an autofocus IC.
And the distance measurement unit consisting of PSD and the distance measurement data based on the output of this autofocus IC and CdS
Transfer the photometric data based on the output of and to the main CPU.

The drive IC controls the shutter circuit and outputs the trigger signal of the strobe circuit based on a command from the sub CPU.

FIG. 6 is an explanatory diagram of a zoom-related portion in the block diagram.

From the main CPU, forward rotation and reverse rotation commands are output to the motor drive circuit via four signal lines MP1, MP2, MN1 and MN2.

In addition, the motor power supply control circuit that supplies drive power to this motor drive circuit switches the supply voltage between high and low based on the speed command input from the main CPU via the signal line MCNT. If NCNT is OFF, the battery voltage is directly supplied to the zoom motor drive circuit, and if ON, it is stepped down to a predetermined voltage and supplied.

The contents of these commands are as shown in Table 1 below.

The zoom motor drives the lens barrel 3 through the cam cylinder in the forward rotation direction to change the focal length of the taking lens to the tele side, and drives the lens barrel 3 in the reverse direction to retract the taking lens. The focal length of is changed to the wide side.

In this camera, the change in the focal length of the taking lens, the change in the open F value due to this change, the lens at the wide-angle end, and the telephoto end.
Information such as being in the macro photographing position and being in the storage (lock) position is automatically detected, and various controls are performed according to these information.

Therefore, a code plate is attached to the peripheral surface of the cam cylinder that drives the lens, and a brush that slides on the code plate is attached to the body side.
This is provided (each terminal name: ZC0, ZC1, ZC2, GND).

The GND of the four brushes is a common terminal, and the other three are code detection terminals.

FIG. 7 shows the development of the code plate 13 and the correspondence between the codes. A signal of "0" is taken out from the terminals ZC0, ZC1 and ZC2 when it is in contact with the conductive land of the code plate shown by hatching in the figure, and a signal of "1" when it is not in contact. In this specification, 3-bit information detected from the conduction relationship of these terminals is defined as a zoom code ZCODE.

Further, in this camera, the position code POS and the division code DIV are determined based on the above zoom code for zooming control.

The position code POS is that the shooting lens is on the lock position side from the wide end, that it is at the wide end of the zoom range, that it is at the tele end, that it is in the zoom range between the wide end and the tele end, and that it is at the macro position from the tele end. Used to distinguish the five states of being on the side, the division code DIV is
It is used to indicate the lens position by dividing the zoom range into 14 parts. DIV in the figure is displayed in hexadecimal.

In FIG. 7, the portion of POS = 1, 3 is also expressed with a certain width, but this portion does not actually have a width. That is, POS becomes 1 when the lens is set to the wide end, that is, ZC1 is 1 to 0.
Only at the moment (OFF to ON), if it does not stop at the wide end, POS will switch from 0 to 2.

By the way, in this device, a stop prohibition area is provided between the lock position and the zoom area and between the home area and the macro position.

However, if the above-mentioned boundary distinction is detected by the change of the terminal from ON to OFF, if the terminal that is originally ON is detected as OFF due to poor contact between the brush and the code plate, the zoom motor May stop in the prohibited area.

With this, in this device, the code plate and the software are configured to use the change of the predetermined terminal from OFF to ON in detecting these boundaries. With such a configuration, since the ON state is not detected in the area where the terminal is OFF, even if there is a contact failure between the brush and the cord plate, the stop at the stop prohibition position can be avoided.

On the other hand, in the zoom range, 14 divisions are made according to the focal length of the taking lens as described above. Moreover, the terminal ZC2
Is used only for tele edge detection in the zoom range.

Therefore, 13 steps must be divided into 2 bits. So, in this example, the ZCO
It uses a relative code structure that repeatedly corresponds DE = 4,5,6,7.

With such a configuration, it is not possible to specify one division code corresponding to the focal length of the lens only from the statically detected zoom code ZCODE, so the change of the zoom code from the end point is changed. It is configured to detect the current division code by sequentially rewriting the division code stored in the memory while automatically detecting it.

Next, the functions of the mode button A and the mode button B will be described.

The mode button A has the function of setting the exposure method. As the exposure method, here, auto (strobe automatic flash mode), strobe ON (strobe configuration flash mode), strobe OFF (strobe flash off mode), exposure Six types of correction, bulb, bulb & strobe ON are prepared.

FIG. 8 shows the display mark corresponding to each exposure method. It should be noted that in the case of auto, it is not displayed. Also, one MODEA is prepared corresponding to the exposure method. The content of MODEA "0" is auto, "1" is strobe O.
N, "2" corresponds to strobe OFF, "3" corresponds to exposure compensation, "4" corresponds to bulb, "5" corresponds to bulb & strobe ON.
When the mode button A is operated, MODEA is changed.

The mode button B has a function of setting a photographing method, and six kinds of photographing methods are prepared here: one frame photographing, continuous photographing, self-timer, double self, multiple photographing, and interval. Although the display marks corresponding to the respective photographing methods are also shown in FIG. 8, they are not displayed during the single frame photographing. In addition, MODEB is prepared corresponding to the shooting method. The content of this MODEB "0" is single frame shooting, "1" is continuous shooting, "2" is self-timer,
“3” corresponds to double self, “4” corresponds to multiple shooting, and “5” corresponds to interval.

When the mode button B is operated, the contents of MODEB are changed. The LCD display is displayed based on the contents of MODEA and MODEB, and the control at the time of shooting is also performed based on these contents.

The manual shutter time shown in Table 2 is prepared for the exposure method of bulb or bulb & strobe ON. Here, eight types of manual shutter time are prepared, and one MODBLB is prepared for these eight types of manual shutter time. The content "0" of this MODBLB corresponds to the valve, and "1" ~ "7" corresponds to each manual shutter time of 1 to 60 seconds. This modblb
The contents are changed when the zoom lever 10 is operated while the mode button A is being pressed when the mode button A is pressed to change to the valve or valve & strobe ON mode. It should be noted that when the manual shutter time is not displayed in the bulb or bulb & strobe ON mode, the mode button A is pressed again and the zoom lever 10 is manipulated.

The interval times shown in Table 3 are prepared for the shooting method intervals. Here, 16 types of interval time are prepared, and one MODINT is prepared for these 16 types of interval time.
Each content of "0" ~ "15", each interval time 10 seconds ~
It corresponds to 60 minutes. The contents of MODINT are mode button B
When the mode is changed to the interval mode by pressing, the mode is changed by operating the zoom lever 10 while pressing the mode button B. It should be noted that when the interval time is not displayed in the interval mode, the mode button B is pressed and the zoom lever 10 is operated to change it. In addition,
The initial value of the manual shutter time is a valve, and the initial value of the interval time is 60 seconds, which is automatically set when the mode initialization or clear button C is turned on.

Next, the display contents of the ICD display 9 will be described with reference to FIG. The mode marks by the mode buttons A and B are displayed in the respective display areas according to the respective modes, and the meanings of the respective marks have already been described, so the remaining marks will be described.

In FIG. 9, 17 is a shutter button mark, 18
Is a macro mark, 19 is a zoom lever mark, 20 is a battery mark, 21 is a 7-segment display unit, "mm" is a mark of the unit that lights up when the focal length is displayed, and "MS" is a manual shutter time or interval time. Is a unit mark when displaying, and “EX” is a unit mark indicating the number of shots.

The shutter button mark 17 is displayed when the shutter button 15 is operable, and the macro mark 18 is the macro button 16
Lights when the shooting lens is extended to the macro position by pressing and macro shooting is possible, and it flashes when it is necessary to switch to macro shooting as a result of distance measurement. The zoom lever mark 19 is lit or blinked when the zoom lever 10 is usable, and the battery mark 20 is lit when the battery is exhausted. Numerical values corresponding to the number of shots, focal length, manual shutter time, or interval time are displayed on the 7-segment display unit 21. In addition, in the unit mark "MS",
"M" means minutes and "S" means seconds, and either "M" or "S" is displayed corresponding to the set time of the manual shutter time or the interval time.

Next, the program stored in the above-mentioned main CPU will be described along with the operation of the camera according to the flowcharts shown in FIGS.

<< Main Process >> First, the reset process and the main process shown in FIGS. 10 to 15 will be described. The main processing defines the basic operation of the camera, and other processing is performed by being branched or called from the main processing according to various conditions.

When the power is turned on, the reset of the main CPU is released,
The reset process of FIG. 10 is started. The main CPU performs memory initialization and switch data input at step RS1 and RS2 (hereinafter referred to as S.), mode initialization at S.RS3, and 16th at S.RS4.
After performing the zoom initialization processing shown in the figure, the main processing is started. The mode initialization process is a process for returning the settings of the various modes described above to the initial values and setting the mode for automatic flash emission and single frame shooting.

In the main process, the 1 second timer used for display hold in S.MI1 is cleared and started.

For S.MI2 to MI4, metering switch SWS, relays switch S
WR, Wide switch WIDE, Tele switch TELE, Mode A
Switch MDA, Mode B switch MDB, Clear switch MD
When all of C and the micro switch MCRO are OFF, 1 is set to the switch judgment flag? SWOFF and any of them is turned ON.
If so, 0 is set. In the following description, the flag name will be prefixed with "?" To distinguish it from other symbols.

For S.MI5 to MI8, metering switch SWS, relays switch S
When all four switches of WR, wide switch WIDE, and tele switch TELE are OFF, and the combination of modes that prohibits shooting is not selected in the mode setting, 1 is set to the metering switch valid flag? SWSEN. , 0 is set when any of the switches is turned on, or when the photographing prohibited mode combination is set.

In S.MI9, the states of the respective switches described above are input, and thereafter, processing is performed based on the input switch data.

First, when it is determined in S.MI10 that the rewind switch REW is ON, the mode initialization processing is performed in S.MI11, and then the loop exit processing shown in FIG. 12 is performed in S.WI12. This process consists of two steps, S.LO1 that stops charging the strobe circuit and S.LO2 that turns off the red lamp for charging, and is always called before branching from the main process to other processes. .

After the loop exit processing, the process branches to the rewind processing of S.MI121. The rewind process is not described in detail, but the rewind end flag? R is set when the film rewinding is completed.
EWEND is set to 1, and the process jumps to the beginning of the main process.

When the back cover is closed and the back cover switch BACK is ON,
In S.MI14, it is judged from the state of loading end flag? LDEND whether loading is finished or not, and if it is not finished (? LDEND = 0), mode initialization processing and loop exit processing of S.MI15 and MI16. And through S.MI
It branches to the loading process of 161. If it has ended, S.MI17 and MI18 are skipped and the processing proceeds.

When the loading process is completed,? LDEND is set to 1, and the process jumps to the beginning of the main process to proceed.

If the case back is open, in S.MI17, MI18? LD
END.?REWEND is cleared together.

In S.MI19 to MI24 in Fig. 13, the lock switch LOCK is OFF.
When the power lever is turned on, that is, when the power lever is moved from the power-on position to the power-off position. If it is determined based on the lock position flag? LOCK that the taking lens is not in the lock position, after switching the film number display on the LCD display to the focal length display, the exit processing is performed and the zoom reverse processing described later is performed. Branch and pull the lens back to the locked position. If the lens is already in the lock position and is not in the rewind end state, the process exits the loop and branches to the lock process described later. If it is in the rewind end state, the process proceeds by jumping to the "MID" position of the May process shown in FIG.

The lock switch LOCK is OFF, and the lens is closer to the lock position than the wide end in S.MI25 (POS =
In the case of 0), the focal length is displayed in S.MI26 and MI27, and the display hold flag? WAITD is set to 1 so that the display is held for 1 second. This hold processing will be described at the end of the main processing. Thereafter, in S.MI28, the macro request flag? RQMCR0 is set to 0, and in S.MI29, the exit processing is executed to branch to the zoom forward rotation processing described later to move the lens to the wide end.

In S.MI30 to MI36, when the macro switch MCRO is ON, the focal length is displayed and the display hold flag is displayed.
? WAITD is set to 1. And the macro position flag? M
From the CRO state, it is judged whether or not the taking lens is in the macro position, and if it is in the macro position, the display hold timer is cleared and started, and the process jumps to "MIC" in Fig. 15 to proceed. If it is not in the macro position, the macro request flag? RQMCRO is set to 1, the process branches to the zoom forward rotation process through the loop exit process, and the lens is moved to the macro position.

Then, in S.MI37 to MI43 shown in Fig. 14, the teleswitch
If TELE is on, switch to focal length display and set the display hold flag, and if it is not at the tele end (POS ≠
In 3), after exit processing, it is determined whether it is on the macro side (POS = 4) or on the wide side (POS ≠ 4) from the tele end. If it is in the zoom range wider than the tele end, it branches to the tele movement process described below to move the lens to the tele side, and if it is on the macro side, it branches to the zoom reversal process to move the lens to the tele end. Pull back.

When the lens is already at the telephoto end (POS = 3), the display timer is cleared and counting for 1 second is performed again from this point.

In S.MI44 to MI50, when the wide switch WIDE is ON, the focal length display is switched to and the display hold flag is set, and if the lens is at the wide end, S.MI48
Clear the timer, start it and proceed with the main processing. If it is not at the wide end, it is determined whether the lens is on the wide side or the macro side of the tele end through the loop exit processing.

If it is on the wide side, the process moves to the wide movement processing described later to move the lens to the wide side. If it is on the macro side, it branches to zoom reverse processing and pulls the lens back to the tele end, and if the wide switch WIDE continues to be pressed even after reaching the tele end, it branches from zoom reverse processing to wide movement processing. Then, the lens is continuously moved to the wide side.

Therefore, the macro lens is set to the macro position by turning on the macro switch, and the zoom lever may be operated in either direction to return the lens set to the macro position to the zoom range.

In S.MI51 to MI54 in Fig. 14, the macro teleshift flag? M
When it is judged from the TSIFT state that a shift is requested, the focal length display process is performed, the display hold flag? WAITD is set to 1, and the loop exit process is performed to branch to the zoom reverse process and the lens is moved to the tele end. Pull back to.

In this embodiment, since the long-distance limit for macro photography is about 1 meter, if the lens is in the macro position and the distance measurement result is 1 meter or more, a photograph that is still in focus even if the shutter is released as it is Can't get Therefore, in this camera, the relays lock is applied in the above case, and the lens is controlled to shift from the macro position to the tele end. The flag? MTSIFT is set in the LL calculation process in the AEAF control process.

Then, S.MI55 judges the state of the rewind end flag? REWEND, and if the rewind has ended, S.MI56
To display "00 EX" on the LCD display. When this flag is 0, the mode setting process is called in S.MI57.

The mode setting process starts only when all the switches are turned off by the previous input by checking the switch judgment flag? SWOFF set in S.MI2 to MI4, and when any switch is turned on. Returns to the main process without setting.

In this mode setting process, the exposure method and shooting method are set, and the values corresponding to each method are set in MODEA and MODEB.
When the mode is changed, the mode change flag? MDCHG is set to 1, and when the mode is not changed, it is set to 0.

When returning from the mode setting process, the state of the flag set in S.MI58 is judged, and if the mode is changed, the display hold flag is set to 1 in S.MI59 and MI60 and the loop exit process is executed. Jump to the beginning of the main process.

If the mode is not changed, the status of the photometric switch SWS and the photometric switch valid flag? SWSEN is determined in S.MI61 and MI62, and S.MI63 to MI
At 65, the focal length is displayed, the display hold flag is cleared, and after the loop exit processing, the flow branches to the AEAF control processing for performing shutter-related control.

The branch to AEAF control processing is when the photometric switch is ON, all SWS, SWR, TELE, and WIDE switch data stored in memory are OFF, and the shooting mode is set. Is. That is, the branching to the AEAF control processing is performed only when the SWS changes from OFF to ON, and when the zoom lever is operated, the main processing is continued without branching.

In S.MI66, the charge control process of the strobe circuit is executed, and S.MI66
Display switching processing is executed in MI67 to MI71.

When the display hold is requested, it is determined whether or not one second has passed from the clearing of the display timer in the main process after the zoom process described later, for example.

The actual display is held before the timer elapses for one second.

If a display hold is not requested, or if a timer other than 1 is displayed when the timer has elapsed for 1 second, the number of pieces is displayed and the display hold graph? WAITD
To clear.

In this way, the display of the number of films is preferentially displayed over the other displays except when it is temporarily switched.

And after stopping the 125ms processing in S.MI72, the charge prohibition time processing is called in S.MI73 and after the return, the main processing
The process continues by jumping to S.MI2.

Above, the description of each step of the main processing is completed, and subsequently, the flow and the subroutine branching from the main processing will be described.

<< Zoom initialization processing >> Fig. 16 is a flow of the zoom initialization processing called in S.RS4 of the reset processing.

In this camera, since the zoom code is a relative code as described above, if the battery is removed and the memory contents are discarded, the camera itself cannot grasp the current position of the taking lens. The zoom initialization process is performed to temporarily return the taking lens to the lock position in such a case.

First, in S.ZI1, the zoom code ZCODE is input from the conductive state of the brush slidingly contacting the code plate.

In S.ZI2 to ZI8, if the lens is not in the lock position, the motor is reversely rotated at high speed, and if it is already in the lock position, the zoom motor is normally rotated at high speed for 100 ms and then reversely rotated to pull back to the lock position.

Then, in S.ZI9, the position code POS is set to 0, the lock position flag is set to 1 and the macro position flag is set to 0, and the process returns to the called position.

Next, processing related to zooming, zoom reverse processing, normal rotation processing, tele and wide movement processing will be described, but before that, code check processing frequently called in these processing will be described.

≪Code check process≫ Figures 17 and 18 show the zoom code ZC associated with zooming.
This is a process of determining the predicted change values ZCFOW and ZCREV of the position code POS, the division code DIV, and the zoom code according to the change of ODE.

However, since a part of the zoom code is a relative code, the position code and the division code corresponding to the focal length of the lens cannot be specified as one only from the statically detected zoom code.

Therefore, in this code check process, the position code POS and the division code DIV stored in the memory are sequentially detected while dynamically detecting the change of the zoom code from the lock position (ZCODE = 2) where the zoom code is an absolute code. I am rewriting.

When entering this process, first lock switch LOCK with S.CK1,
Each data of micro switch MCRO, wide switch WIDE, tele switch TELE, speed change switch ZMHL is input. These stitch data are used after the return when the code check process is called in the tele move process, the wide move process or the like which will be described later.

In S.CK2 to CK5, the position code is at the wide end (POS =
1) and the tele end (POS = 3), these are forcibly set to codes indicating the zoom range (POS = 2) and the macro position side (POS = 4) from the tele end, respectively. As mentioned above, position code POS at tele end and wide end
Has no width, it immediately takes on another value when the zoom motor is moving.

Subsequently, the zoom code ZCODE is input by the zoom code input processing of S.CK6, and when there is no change in the zoom code, the process returns to the step called from S.CK7.

When there is a change, different processing is executed depending on the rotation direction of the zoom motor. If the motor is rotating forward,
Proceed from S.CK8 to S.CK9, and in the case of reverse rotation, S.CK25 in Fig. 18
Go to.

The case of forward rotation will be described.

The value of POS becomes 0, 2, or 4 depending on the processing of S.CK2 to CK5.

When the lens is on the lock side from the wide end (POS =
In 0), the process returns from S.CK10 to the called step as it is until the ZC1 terminal of the brush is turned on, that is, until the wide end is reached. When ZC1 is turned ON, POS and DIV are set to 1 in S.CK11, and if the zoom motor is rotating normally, the value of the zoom code that will be taken after the next change (the zoom code is normal). Predicted change in rolling direction) Set ZCFOW to 4 and return.

The predicted change value is determined based on the correspondence table shown in FIG.

If the lens is in the zoom range (POS = 2), S.CK12
To S.CK13, it is determined whether the division code DIV is smaller than 2, and if it is 2 or more, it is determined whether the state of the ZC2 terminal in S.CK14 has reached the tele end.

The ZC2 terminal becomes 0 between the lock position side from the wide end, the zoom range, and the macro position, as shown in FIG. Therefore, theoretically, it is not considered that the ZC2 terminal becomes 0 when POS = 2, and the tele end can be detected without the step of S.CK13.

However, it is conceivable that a region where ZC2 is 0 and a region where ZC1 is 0 partially overlap with each other due to a manufacturing error of the code plate.

Therefore, the judgment of S.CK13 is provided so that the tele end can be detected only from the signal of the ZC2 terminal even if there is such an error.

When the tele end is detected, POS is set to 3 in S.CK15 and CK16,
While setting DIV to EH, change the LCD display to the telephoto focal length display (70mm) and return. In addition,
When entering this flow, the LCD display always shows the focal length display.

If the tele end is not reached, Z in S.CK17, CK18
C2 as 1 and zoom code ZCODE and predicted change value ZCFOW
Compare with. If they are equal, S.CK19 to CK22
In addition to counting up the division code and setting a new predicted change value, display keep flag? K
If PLCD is 0 (display change permission), the focal length display corresponding to the new DIV is performed and the process returns.

When the judgments at S.CK9 and CK12 are both negative, that is, when the lens is on the macro position side from the tele end (POS = 4)
In S.CK23, it is determined whether or not the ZC0 terminal is 0. If it is 0, the macro position flag? MCRO is set to 1 in S.CK24, the macro request flag? RQMCRO is cleared, and the process returns.

If the motor is rotating in the reverse direction, the process jumps to S.CK25 in FIG.

The zoom code ZCODE 2 is an absolute code and means that the lens is in the locked position. In this case, S.CK
Branch from 25 and brake the zoom motor at S.CK26. Then, POS is set to 0 in S.CK27 and CK28, the lock position flag? LOCK is set, and the stack process is performed to jump to the head of the main process.

When the lens is on the macro position side from the tele end (POS =
In 4), the process proceeds from S.CK29 to S.CK30, and while the ZC1 pin is at 1, returns to the called step.

When the ZCl terminal is 0, it is assumed that the lens has entered the zoom range, POS and DIV, and the predicted change value ZC in the reverse direction.
If REV is set and the display change is permitted in S.CK32, the focal length display will be returned to a new value (65mm) in S.CK33.

Next, if POS is not 4, POS = 2 in S.CK34
The processing is divided into the case of POS and the case of POS = 0, and when the lens is on the lock position side from the wide end (returns to POS = 0 as it is).

If the lens is in the zoom range (POS = 2), S.CK35
~ In CK39, it is judged whether the ZC2 terminal is ON (0) on condition that the division code is BH or less, and 0
If so, PO is determined as being on the lock position side from the wide end.
When S is set to 0 and the display change is permitted, the focal length display is changed to a new value (35 mm) and the process returns.
The judgment of S.CK35 considers the manufacturing error of the code plate as in the case of S.CK13 described above.

In S.CK40 and CK41, the ZC2 pin is regarded as 1 and the zoom code
ZCODE is detected and it is determined whether or not this is equal to the predicted change value ZCREV. If they are not equal, return as is,
If they are equal, the division code is decremented by 1 in S.CK42 to CK45, and new change predicted values ZCFOW and ZCREV are set, and if the display change is permitted, the focal length display is returned as a new value.

As mentioned above, the lock position, macro position, tele end, and wide end are all set from OFF (1) of terminals ZC0, 1, 2.
It is detected by the change to ON (0), so that it is possible to prevent a detection error due to poor contact between the brush and the code plate, and avoid a situation where the zoom motor stops at the stop prohibition position.

<< Zoom Reverse Processing >> FIG. 19 is a flowchart showing zoom reverse processing that branches from S.MI22, MI42, MI50, and MI54 of the main processing. This processing includes an operation of retracting the taking lens to the lock position and an operation of returning from the macro position to the zoom range. In addition,
When stopping within the zoom range, a normal rotation operation is included to eliminate the effect of backlash.

The zoom-related processing will be described below with reference to the operation explanatory view shown in FIG.

When branching to this flow, first, in S.ZR1 and ZR2, the macro teleshift flag? MTSIFT and the macro position flag? MCRO are cleared, and the zoom motor is reversed at high speed.

In S.ZR3, the display keep flag? KPLCD is set to 1 to prohibit the change of the focal length display, and in S.ZR4 and ZR5, the code check is repeated when the lens is on the macro position side from the tele end.

When the lens is set to the zoom range side from the tele end,
Or, if the zoom range is entered while repeating the determination of S.ZR5, ON / OFF of the lock switch LOCK is determined by S.ZR6.

When the lock switch is ON, the display keep flag? KPLCD is cleared in S.ZR7. And S.ZR8
In ZR13, the motor is reversely rotated until the lens reaches the lock position or the lock switch is turned off, and when the lock position is reached, the motor is stopped and the main process is jumped to and the process is continued. The movement in this case is shown by the symbol a in FIG.

If the lock switch is turned off before the wide end is exceeded by the reverse rotation of the zoom motor, S.ZR14 to ZR23 reverses the switch for 70 ms and then rotates it forward for 50 ms.If the lens is in the home range, stop it as it is. Let (20th
(The movement indicated by reference numeral b in the figure). If the lens is on the lock position side from the wide end even after the normal rotation, the motor forward rotation is continued up to the wide end and is extended to the wide end, and then the motor is stopped (the movement indicated by the symbol c in FIG. 20). . In either case, the focal length is displayed and the process is continued by jumping to the beginning of the main process.

On the other hand, if the lock switch has been off from the beginning, proceed from S.ZR6 to S.ZR24, and if the wide switch is on, go to "JPWIDE" for wide movement processing, which will be described later.
The processing is continued by jumping to the terminal. If not, 50ms after zoom becomes in S.ZR25 to ZR30
After the lapse of time, the motor is rotated at a high speed in the normal direction, the lens is set to the tele end, and the process jumps to the main process (the movement indicated by the symbol d in FIG. 20).

In the case of zoom reverse rotation processing, or when this reverse rotation processing is entered from the "STOPWD" terminal of wide movement processing, 50 ms after the motor reverse rotation stop is performed in order to eliminate backlash.
Rotate the motor forward for a while and then stop the motor. Therefore, if you do not prohibit changing the focal length display, the DI
When entering the V area, a short focal length is displayed,
There is a case where the display is switched to a display with a long focal length when it is inverted and enters the DIV area on the tele side. Such a change in display may give the user an impression as if a malfunction occurred on the telephoto side immediately before the stop despite the movement of the focal length to the wide side. Therefore, in this case, the display keep flag? KPLCD is set to temporarily suspend the change in the display and permit the change when the zoom motor is stopped.

<< Zoom Normal Rotation Process >> FIG. 21 is a flowchart showing the zoom normal rotation process branched from S.MI29 and MI36 of the main process. This processing moves the photographing lens from the lock position to the wide end or from the zoom range to the macro position.

When the process of normal rotation of the zoom motor is started, first, the lock position flag? LOCK is cleared in S.ZF1 and ZF2, and the zoom motor is normally rotated at high speed. In S.ZF3 to ZF6, after confirming that the lens is on the zoom range side from the wide end, if there is no macro request, stop the motor and jump to the main processing. This is as shown by the symbol e in FIG.
This is the process of moving the lens from the lock position to the wide end when the power lever is in the power ON position.

If there is a macro request, in S.ZF7 to ZF9, wait for the lens to pass the tele end of the zoom range on condition that the lock switch is OFF, and if the lock switch is ON, S.ZF10
Stop the motor and jump to the main process. When the lens passes the tele end, the motor is stopped after the macro position flag? MCRO is set in S.ZF11 to ZF13 (movement indicated by the symbol f in Fig. 20), and the process jumps to the main process for processing. Can be advanced. This is the operation when the macro button 16 is pressed in the state of the power lever power ON position (lock switch OFF).

As shown in the above-described zoom motor reverse rotation and normal rotation processing, the lens drive by the operation of the power lever or the macro button 16 is performed at high speed.

<< Tele Movement Processing >> FIG. 22 is a flowchart showing the tele movement processing branched from S.MI42 of the main processing.

This processing is executed by turning on the tele switch TELE when the taking lens is in the zoom range.
It is common to the above-described zoom forward rotation process in that the zoom motor is normally rotated to move the photographing lens, but is different in that the zooming speed can be switched at high speed.

When entering the tele-movement processing, first the zoom motor is normally rotated at high speed in S.ZT1, and the speed switching timer is cleared and started in S.ZT2.

In S.ZT3 to ZT10, 30ms at startup is driven at high speed on condition that the tele switch is ON, the lens has not reached the tele end (POS ≠ 3), and the lock switch is OFF. Then, after 30 ms has elapsed, the motor is rotated normally by switching between high speed and low speed according to the selection of the speed switch.

When the tele switch TELE is turned off in the zoom range, the operation is as indicated by the symbol g in FIG. Further, the operation when reaching the tele end is indicated by the symbol h.

When the above conditions are not satisfied, S.ZT
At 11, the motor is stopped and the process proceeds to the beginning of the main process.

<< Wide Movement Processing >> FIG. 23 is a flowchart showing the wide movement processing branched from S.MI50 of the main processing.

This process is executed when the shooting lens is in the zoom range and the wide switch WIDE is turned on, and is the same as the zoom reverse processing described above in that the shooting lens is moved in the retracted direction, but the zooming speed is switched. Possible points are common to the tele-movement processing.

In the wide movement process, first, the zoom motor is reversed at high speed in S.ZW1, and the timer is cleared and started in S.ZW2. When the process is branched from S.ZR24 of the above-described zoom inversion process, the processes of S.ZW2 and below are common.

In S.ZW3 to ZW10, the wide switch is ON,
If the lens is not in the lock position side from the wide end (POS ≠ 0) and the lock switch is OFF, drive 30 ms during excitation at high speed, and after 30 ms, the speed change switch The motor is rotated in reverse by switching between high speed and low speed according to the selection.

If the wide switch WIDE is turned off, set the motor rotation to high speed in S.ZW11 and then
The process branches to S.ZR14, and a process for eliminating the influence of backlash is executed (movement indicated by reference sign i in FIG. 20).

Wide switch WIDE is turned off in the zoom range, and the above 70ms
If the lock position is on the lock position side from the wide end at the time point when the normal rotation and the reverse rotation of 50 ms are completed, the zoom motor is stopped and extended to the wide end as indicated by the symbol j in FIG.

If the lens enters the lock position side from the wide end,
After setting the motor to high speed with S.ZW12, wait 50 ms for S.ZW13 to ZW17 to reverse the zoom motor, set the lens to the wide end while removing the backlash, and stop the motor (see Fig. 20). (Movement indicated by reference character k), and jumps to the main processing.

When the lock switch is turned on, the motor is stopped at S.ZW18 and the main processing starts. In this case, the main processing is branched to the zoom reverse processing and the lens is pulled back to the lock position.

<< Lock Processing >> FIG. 24 shows the flow of the lock processing branched from S.MI24 of the main processing. This process is a process that is branched and executed when the lock switch is turned on and the taking lens is stored in the lock position.

When this processing is entered, the number display is turned on or off on the LCD display according to the state of the loading end flag? LDEND in S.LK1 to LK4, and the mode is returned to the initial value.

Rewind switch REW is OFF for S.LK5 to LK13 loops
That the back cover switch BACK is OFF, but ON
Even if it is done, it is executed repeatedly for 125 ms on condition that the loading is completed and the lock switch is ON.

In S.LK13, the same charge prohibition time processing as in S.MI73 of the main processing is performed.

When the rewind switch is turned on, the process branches from S.LK6, executes the rewind process of S.LK61, and jumps to the beginning of the main process.

When the back cover is closed and loading is completed, S.LK9 and LK10 are skipped to form a loop. When the back cover is opened, the loading end flag is cleared and the number of sheets display is turned off. To be done. If the back cover is closed in the next loop, the process proceeds from S.LK8 to S.LK81 loading process, and when this process ends, the process jumps to the beginning of the main process.

When the lock switch LOCK is turned off, charge start flag? CHGST and display hold flag? WAITD in S.LK14, LK15
And are set to 1 and the process proceeds by jumping to the main process.

[Effects] As described above, the lens position detecting device for a camera according to the present invention has the code plate configured to use the change of the predetermined terminal from OFF to ON in detecting the passage of the stop prohibited area. Even when the predetermined area is the stop prohibited area of the lens, the zoom motor does not stop in the stop prohibited area due to poor contact between the brush and the code plate.

[Brief description of drawings]

The drawings show a camera equipped with the lens position detection of the camera according to the present invention. 1 to 3 show the appearance of the camera. FIG. 1 is a plan view, FIG. 2 is a front view, and FIG. 3 is a rear view. FIG. 4 is a block diagram of a control circuit, FIG. 5 is an explanatory diagram of a contact structure of a zoom switch, FIG. 6 is a block diagram of a zoom motor control system, and FIG. 7 is a development view of a code plate and code plates and respective codes. FIG. 8 is a diagram for explaining mode setting, and FIG. 9 is a diagram for explaining LCD display segments. FIG. 10 to FIG. 19 and FIG. 21 to FIG. 24 are flowcharts showing the function of the electric zoom device of this embodiment.
The figure shows the reset processing, and the figures 11, 13, 14, and 15 show the main processing, the first
Figure 2 shows loop exit processing, Figure 16 shows zoom initialization processing, Figures 17 and 18 shows code check processing, Figure 19 shows zoom reverse processing, Figure 21 shows zoom forward processing, Figure 22 shows tele movement processing, FIG. 23 shows the wide movement process, and FIG. 24 shows the lock process. FIG. 20 is a diagram for explaining the zooming operation.

Front Page Continuation (72) Inventor Norio Numako 2-36 Maenocho, Itabashi-ku, Tokyo Asahi Kogaku Kogyo Co., Ltd. (72) Katsutoshi Nagai 2-36-9 Maenocho, Itabashi-ku, Tokyo Asahikari (56) Reference JP-A-2-12211 (JP, A) JP-A-2-123311 (JP, A) JP-A-1-296207 (JP, A)

Claims (1)

[Claims] 1. A code plate having a pattern of a conducting portion and a non-conducting portion to divide the zoom lens position into a plurality of regions.
A plurality of brushes that relatively move while slidingly contacting the code plate to detect contact and non-contact with a conductive portion of the code plate, and a lens driving zoom motor that is controlled based on signals from the brushes. In a lens position detection device for a camera, in which a predetermined area is a stop prohibition area of a lens, an end point of the stop prohibition area is detected at a point where the brush switches from a non-conducting portion to a conducting portion of the code plate. A lens position detection device for a camera having a configuration.