JPH02210411A - Lens position detector of camera - Google Patents

Abstract

PURPOSE:To prevent the stop of a zoom lens in a stop inhibition area thereof by executing the end point detection of the stop inhibition area at the point where brushes change from the nonconducting part of a code plate to the conducting part. CONSTITUTION:The code plate is stuck to the peripheral surface of a cam cylinder for driving a lens and the brushes ZC0, ZC1, ZC2, GND which come into sliding contact with the code plate are provided on the body side. The part between a lock position and a zoom area and the part between the zoom area and a macro position are defined as the stop inhibition areas. The code plate and software are so constituted as to use the change of prescribed terminals from off to on at the time of detecting the boundary of these areas. The detection that the terminals are on in the region where the terminals are ought to be off is obviated in this way and, therefore, the stop in the stop inhibition position is averted even if there is a contact defect between the brushes and the code plate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens position detection device that electrically detects changes in focal length, etc. of a zoom lens accompanying zoom operations.

[Prior Art] In cameras equipped with a zoom lens, it is necessary to know the f-number of the photographing lens at the time of shooting in order to calculate exposure, and in cameras equipped with an electric zoom device, it is necessary to know the f-number of the photographing lens at the time of shooting. It is necessary to know what mm the focal length of the lens is set to.

Therefore, conventionally, a code plate is attached to the cam barrel for driving the zoom lens so that it rotates together with the cam barrel, and a brush is provided on the body side that slides into contact with the code plate, and the conduction state of the brush is detected. The lens position is determined from the zoom code.

[Problem to be Solved by the Invention] By the way, the above-mentioned zoom code has a conductive relationship between the ground brush that is in constant contact with the conductive pattern of the code plate and the code brush that switches between the conductive part and the non-conductive part of the code plate. detected by.

However, since the brush and the code plate have a mechanical structure, there is a possibility that the code brush may be lifted off the code plate due to external factors such as vibration.

Within the driving range of the photographic lens, a prohibited stop area may be set, for example, between the storage position and the photographable position. If the configuration is such that passage through the stop prohibited area is detected by the change of the brush from ON to OFF, there is a risk that the terminal that is originally ON will be detected as OFF due to the brush floating, and the zoom motor will stop in the stop prohibited area. be.

[Object of the invention] This invention was made in view of the above problems, and
To provide a lens position detecting device for a camera that prevents a zoom lens from stopping in a stop prohibited area even when brush lifting occurs.

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

With such a configuration, O in the area where the terminal is OFF
Since N is never detected, even if the brush is lifted, stopping at the stop prohibited position can be avoided.

[Example] The present invention will be explained below based on the drawings.

1 to 24 show an embodiment of the present invention.

First, the appearance of a camera equipped with a lens position detection device according to this embodiment will be described with reference to FIGS. 1 to 3.

In FIG. 1, 1 indicates a camera body, and 2.3 indicates a zoom lens barrel. On the front side of the camera body 1, there is a second
As shown in the figure, a distance measuring section 4, a finder window 5, a strobe 6, a CdS as a light receiving element, and a self-timer lamp 7.
are provided, and on the back side of the camera body 1 are a back cover 8, an LC
D display 9, mode button A, mode button B, clear button C, zoom lever 10, green lamp D, red lamp E,
A back cover opening/closing lever 11 is provided, and the back cover 8 is opened when the back cover opening/closing lever 11 is operated in the direction of the arrow from its upward stop position toward its downward stop position. When the back cover 8 is open, the back cover opening/closing lever 11 is at the lowering stop position, and when the back cover 8 is closed, the back cover opening/closing lever 11 is raised.

The back cover 8 is provided with a date display section 12 and a date switching button 13. Note that a rewind button (not shown) is provided at the bottom of the camera body l.

As shown in FIG. 1, the top of the camera body 1 includes a main switch 14, a shutter button 15, and a macro button 1.
6 is provided. The main switch 14 is slid between an ON position and an OFF position.

The zoom lever 10 is moved between the wide side and the telephoto side as indicated by the arrow r1.
, r2 direction. This zoom lever 10 is also used to change the manual shutter time or interval time, which will be described later, but this will be explained all at once when explaining the functions of mode button A, mode button B, and clear button C. shall be.

Next, the circuit configuration of the above-mentioned camera will be explained based on FIG. 4.

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

The main CPU performs the following controls based on input from information input means such as switches.

(1) Control the zoom motor and film motor via each motor drive circuit.

(2) Controls lighting and blinking of the green lamp for distance measurement related displays, the red lamp for flash related displays, and the self-timer lamp 7 for self-timer related displays.

(3) Control the display on the LCD display 9.

(4) Control charging of the strobe circuit.

As a means of inputting information to the main CPU,
There are the following:

(1) A lock switch LOCK that is turned on when the slide lever of the main switch 14 is set to the lock position.

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

(3) Release switch SWR that is turned on by pressing the shutter button 15 in two steps.

(4) A self-back macro switch MCRO0 that is turned on when the macro button 16 is pressed. (5) A zoom tele switch T E LE that is turned on when the zoom lever 10 is tilted to the telephoto side r2.

(6) Zoom wide switch WIDE, which is turned on by tilting the zoom lever 10 to the wide side r1.

(7) Speed changeover switch ZM)IL that is turned on when the tilt angle of the zoom lever 10 is small and turned off when it is large.

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

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

(10) Zoom code input means ZCO and ZCI described later
,ZC2゜(11) When the back cover opening/closing lever 11 is pushed down, the back cover switch turns OFF. When the back cover 8 is closed and the lever moves to the lock position, the back cover switch BACK turns ON.

(12) Self-back rewind switch REW that is activated by pressing the rewind button.

Three zoom-related switches LE, WIDE, ZM)
The IL is configured to perform 0N10FF with one zoom lever, and the arrangement of its contacts is as shown in FIG. These combinations allow the main CPU to control five different states.
The data can be used in zoom operations or in mode settings.

For example, when performing a zoom operation, information regarding forward/reverse rotation of the zoom motor and switching between high speed and low speed for each rotation is input to the main CPU as shown in the figure.

On the other hand, the sub CPU controls a distance measurement unit consisting of an infrared LED and a PSD via an autofocus IC, and also outputs distance measurement data based on the output of the autofocus IO and photometry data based on the output of the CdS. is transferred to main CP[I.

The drive Ic controls the shutter circuit and outputs a trigger signal to the strobe circuit based on instructions from the sub CPU.

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

From the main CPU, four wires HPI, MP2. Forward rotation and reverse rotation commands are output via HNI and MN2.

In addition, the motor power control circuit that supplies drive power to this motor drive circuit is connected to the main CPU via a signal line MCNT.
Based on the speed command input from the controller, the supply voltage is switched between high and low. When MCNT is OFF, the battery voltage is directly supplied to the zoom motor drive circuit, and when MCNT is ON, the voltage is stepped down to a predetermined voltage and then supplied.

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

When the zoom motor rotates forward, it drives the lens barrel 3 through the cam barrel in a protruding direction to change the focal length of the photographic lens toward the telephoto side, and when it rotates in reverse, it drives the lens barrel 3 in a direction that retracts the photographic lens. Change the focal length of the camera to the wide side.

In addition, with this camera, changes in the focal length of the photographic lens, changes in the aperture f-number associated with this change, and changes in the lens' wide-angle (
The camera automatically detects information such as whether the camera is at the wide end, telephoto end, macro shooting position, or stowed (locked) position, and performs various controls based on this information. ing.

Therefore, a code plate is attached to the circumferential surface of the cam cylinder that drives the lens, and four brushes (terminal names: ZCO, ZC: 1, ZC2, GND) that slide into contact with this code plate are provided on the body side. .

Of the four brushes, GIII) is a common terminal, and the other three
The book is the terminal for code detection.

FIG. 7 shows the correspondence between a developed view of the code plate 13 and each code. When the terminals ZCO, ZCI, and ZC2 are in contact with the conductive lands of the code board indicated by diagonal lines in the figure,
0", and when there is no contact, a signal of "1" is taken out. In this specification, 3-bit information detected from the conduction relationship between these terminals is defined as a zoom code ZCODE.

Further, in this camera, a position code PO8 and a division code DIV are determined based on the above-mentioned zoom code for zooming control.

Position code PO8 indicates that the photographing lens is closer to the lock position than the wide end, that the lens is at the wide -9 to 10- end of the zoom range, or at the telephoto end, or that the lens is in the zoom range between the wide end and the telephoto end. The division code DIV is used to distinguish between the five states of being closer to the macro position than the telephoto end, and the division code DIV is used to divide the zoom range into 14 and indicate the lens position. DIV in the figure is a hexadecimal notation.

Note that in FIG. 7, the portions PO2-4 and PO2-3 are also expressed as having a constant width, but this portion actually has no width. In other words, PO2-4 occurs when the lens is set at the wide end, that is, when the lens is set at the wide end,
Only at the moment when I changes from 1 to 0 (ON to 0FF),
If the camera does not stop at the wide end, POS switches from 0 to 2.

By the way, in this device, the areas between the lock position and the zoom range and between the zoom area and the macro position are prohibited areas.

However, if the configuration is such that the distinction between the upper and lower boundaries is detected by the change of the terminal from ON to OFF, if the terminal that is originally ON is detected to be OFF due to the brush floating, the zoom motor will move to the stop prohibited area. There is a risk that it will stop.

Therefore, in this device, the code board and software are configured to use the change of a predetermined terminal from OFF to ON to detect these boundaries.

With such a configuration, O in the area where the terminal is OFF
Since N is never detected, even if the brush is lifted, stopping at the stop prohibited position can be avoided.

On the other hand, in the zoom range, as described above, there are 14 classifications corresponding to the focal length of the photographic lens.

Moreover, the terminal ZC2 is used only for detecting the telephoto end within the zoom range.

Therefore, 13 stages must be divided by 2 bits. Therefore, in this example, a relative code structure is adopted in which ZC=4.5 and 6.7 are repeatedly made to correspond to DIV=1 to E.

When such a configuration is adopted, it is not possible to specify a division code corresponding to the focal length of the lens only from the statically detected zoom code ZCODE, so changes in the zoom code from the end point cannot be determined. It is configured to dynamically detect and sequentially rewrite the division code stored in the memory to hold the current division code.

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

Mode button A has the function of setting the exposure method, and the exposure methods here include auto (strobe automatic flash mode), strobe ON (strobe forced flash mode),
Six types are available: strobe 0FF (strobe flash prohibition mode), exposure compensation, bulb, bulb, and strobe ON.

FIG. 8 shows display marks corresponding to each exposure method. Note that in the case of auto, there is no display. In addition, one MODEA is prepared corresponding to the exposure method, ``HODEArO'' is auto, ``1'' is strobe ON.
, "2" is strobe OFF, "3" is exposure compensation, "4"
"5" corresponds to the valve and "5" corresponds to the valve and strobe ON.

When mode button A is operated, MODEA is changed.

The mode button B has a function of setting a shooting method, and six types of shooting methods are prepared here: single-frame shooting, continuous shooting, self-timer, double self-timer, multiple shooting, and interval shooting. Display marks corresponding to each photographing method are also shown in FIG. 8, but are not displayed when single-frame photographing is performed. In addition, MODB is also available depending on the shooting method.
B is prepared, and this MODEBrO, is for single-frame shooting, "1" is for continuous shooting, "2" is for self-timer, and "3" is for continuous shooting.
” corresponds to double selfie, “4” corresponds to multiple shooting, and “5” corresponds to interval.

When mode button B is operated, MODEB is changed. Display is performed on the LCD based on these HODEA and MODEB, and control during photographing is also performed based on these.

When the exposure method is bulb or pulp & strobe ON,
Manual setting times shown in Table 2 are prepared. Here, 8 types of manual shutter times are prepared, one MODBLB is prepared for these 8 types of manual shutter times, and this MODBLBr is prepared.
O, corresponds to the bulb, and "1" to "7" correspond to each manual shutter time of 1 to 60 seconds. This MOD
BLB is changed by operating the zoom lever 1o while pressing the mode button A when the mode button A is pressed to change to the bulb or bulb & strobe ON mode in the mode setting flow described later. Note that the time can also be changed by pressing the mode button A again and operating the zoom lever 10 when the manual shutter time is not displayed in the bulb or bulb & strobe ON mode.

The interval times shown in Table 3 are prepared for the intervals of the imaging method. Here, 16 types of interval times are prepared, and one MODINT is prepared for these 16 types of interval times.
Each content of MODINT "o" to "15" corresponds to each interval time of 10 seconds to 60 minutes. M.O.D.I.
NT is changed by operating the zoom lever 1o while pressing the mode button B when changing to the interval mode by pressing the mode button B. Note that the interval time can also be changed by pressing the mode button B and operating the zoom lever 10 when the interval time is not displayed in the interval mode. Note that the initial value of the manual shutter time is bulb, and the initial value of the interval time is 60 seconds, which are automatically set when the mode initialize or clear button is turned on.

Next, the display contents of the LCD display 9 will be explained with reference to FIG. Mode marks created by mode buttons A and B are displayed in each display area according to each mode.
Since the meaning of each mark has already been described, the remaining marks will be explained.

In this Figure 9, 17 is the shutter button mark;
18 is the macro mark, 19 is the zoom lever mark, 20
is the battery mark, 21 is the 7-segment display, and rm
mJ is the unit mark that lights up when displaying the focal length, rM
s is a unit mark for displaying manual shutter time or interval time, and rEXJ is a number mark indicating a shooting unit.

The shutter button mark 17 is displayed when the shutter button 15 is operable, and the macro mark 18 is lit when the macro button 16 is pushed and the photographing lens is extended to the macro position and macro photography is possible, and macro photography is performed as a result of distance measurement. Flashes when switching to is required. The zoom lever mark 19 lights up or blinks when the zoom lever 10 is usable, and the battery mark 20 lights up when the battery is exhausted. The 7-segment display section 21 displays numerical values corresponding to the number of shots, focal length, manual shutter time, or interval time. In the time unit mark rMsJ, "rH" means minutes and "S" means seconds, and either rH or "S" is displayed corresponding to the set time of the manual shutter time or interval time. .

Next, the programs stored in the two main CPUs will be explained along with the operation of the camera according to the flowcharts shown in FIGS. 10 to 24.

(The following are blank spaces) Table 1 Table 2 Table 3 (Main Processing) First, the reset processing and main processing shown in FIGS. 10 to 15 will be explained. The main process defines the basic operation of the camera, and other processes are branched from or called from the main process depending on various conditions.

When the power is turned on, the reset of the main CPU is canceled and the reset process shown in FIG. 10 is started. main cpo
Steps (hereinafter referred to as S) perform memory initialization and switch data input in R3I and R82, mode initialization processing in S and R83, and zoom initialization processing shown in FIG. 16 in S and R34. After that, enter the main process. Note that the mode initialization process is a process for returning the settings of the various modes described above to their initial values, and setting the mode to automatic strobe light emission and single-frame photography.

In the main processing, a 1 second timer used for display hold is cleared and started in S and Mll.

S, MI2 to MI4, photometry switch SWS, release switch 5lllR, wide switch WIDE, tele switch TELE, mode A switch MDA, mode B
Is the switch judgment flag activated when switch MDB, clear switch MDC, and macro switch MCRO are all OFF? 1 is set in swopp and one is ON
If it is set to L, 0 is set. In the following description, flag names are distinguished from other symbols by adding a "?" to the beginning of the word.

In S, MI5'-MI8, all four switches, metering switch SWS, release switch SWR, wide switch WIDE, and tele switch position H, are OFF, and a mode combination in which shooting is prohibited is selected in the mode setting. Is the metering switch enabled flag if not? 5
WSEN is set to 1 and 0 is set when any switch is turned on or when a mode combination in which photographing is prohibited is set.

In S and MI9, the status of each switch mentioned above is input,
Thereafter, processing is performed based on this input switch data.

First, if it is determined that the rewind switch REW is ONL in S, old 10, the mode initialization process is performed in S, Mllll, and then the first
The loop extraction process shown in FIG. 2 is performed. This process consists of two steps: S, LO1, which stops charging the strobe circuit, and S, LO2, which turns off the red lamp for charging indication, and is always called before branching from the main process to other processes. .

After the loop extraction process, the process branches to the rewind process.

I won't go into details about the rewind process, but when the film finishes rewinding, is there a rewind end flag? REWEN
D is set to 1, and the process jumps to the beginning of the main process.

If the back cover is closed and the back cover switch BACK is ONL, the loading end flag in S and old 14? L
It is determined from the state of DEND whether or not loading has finished, and if it has not finished (?LDEND=O), S, Mll5. The process branches to the loading process through the mode initialization process and the loop extraction process of Mll6. If completed, S, old 17. Processing proceeds by skipping MT18.

Furthermore, what happens when the loading process is finished? LDEND is set to 1, and the process jumps to the beginning of the main process.

If the back cover is open, S, old 17. In M118? LDEN, D,? RE Stomach END is cleared together.

S and M+19 to old 24 in FIG. 13 show the processing when the lock switch LOCK is ONL, that is, when the main switch is turned off. Lock position flag? If it is determined that the photographing lens is not in the lock position based on LOCK, the film number display on the LCD display is switched to the focal length display, the extraction process is performed, and the process branches to the zoom reversal process described later. to return the lens to the locked position. If the lens is already in the lock position and the rewind is not finished, the process branches to the lock process, which will be described later, via the loop extraction process. If the rewind is completed, the process jumps to the rMIDJ position of the main process shown in FIG. 15 and proceeds.

When the lock switch LOCK is OFF and the lens is closer to the lock position than the wide end (pos=o) in S, old 25, S, )1126. In the old 27, the focus side separation display is performed and the display hold flag?
Set WAITD to 1 and hold the display for 1 second.

This hold processing will be explained in detail in the main processing.

After that, S, MI2B macro request flag? RQHCR
O is set to 0, the extraction process is executed in S and M129, the process branches to the normal zoom rotation process to be described later, and the lens is moved to the wide end.

S, old 30~M■36 Te displays the focal length and displays the display hold flag when the macro switch MCRO is ONL. Set WAITD to 1. And the macro position flag? It is determined whether the photographing lens is in the macro position from the state of MCRO, and if it is in the macro position, the display hold timer is cleared, started, and the 15th
Jump to rMlcJ in the figure and proceed with the process.

If it is not in the macro position, is it a macro request flag? RQHCRO
is set to 1, the loop extraction process branches to the zoom normal rotation process, and the lens is moved to the macro position.

Next, in S, old 37 to old 43 shown in Fig. 14, when tele switch position E is ONI, it switches to focal length display and sets the display hold flag, and when it is not at the tele end (pos≠3 ) is on the macro side (PO2-4) or on the wide side (PO8) after the extraction process.
≠4). If the zoom range is on the wide side from the telephoto end, it branches to the telephoto movement process described later to move the lens to the telephoto side, and if it is at the macro position, it branches to zoom reversal processing to move the lens to the telephoto end. Pull back to.

If the lens is already at the telephoto end (POS=3), the display timer is cleared and the 1 second count is started again from this point.

S, old 44 to old 50, wide switch WIDE is O
If it is NL, switch to focal length display and set the display hold flag, and if the lens is at the wide end, press S, start the timer with BT4B, 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 macro side from the telephoto end through loop extraction processing.

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

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

S in Figure 14, in old 51 to MT54, is the macro tele shift flag? When it is determined that a shift is requested from the state of MTSTFT, focal length display processing is performed and the display hold flag? WAITD is set to 1, and after loop extraction processing, the process branches to zoom reversal processing and returns the lens to the telephoto end.

The long-distance limit for macro photography is approximately 1 meter, so if the lens is in the macro position and the distance measurement result is 1 meter or more, you may not be able to obtain a focused photo even if you release the shutter. Can not.

Therefore, in this camera, in the above case, the lens is locked and controlled to shift the lens from the macro position to the telephoto end. flag? HTSIFT is set in the LL calculation process in the AEAF control process, which will be described later.

Next is S, in the old 55, the rewind end flag? REW
The state of ENII is determined, and if the rewind is completed, S and MT56 cause the LCD display to display rho EXJ. If this flag is O, S, old 57
The mode setting process is called.

In the mode setting process, S, switch judgment flag set in old 2 to MT4? Checking 5WOFF, the setting process is entered only if all the switches were OFF at the previous input, and if any switch was ON, the process returns to the main process without performing any setting.

If there is a mode change during this mode setting process, the mode change flag? ADC) IG is set to 1, and is set to 0 if there is no change.

When returning from the mode setting process, the state of the flag set in S and MI58 is determined, and if there is a change in mode 26, the display hold flag is set to 1 in S and MI59, 8+60, and the loop is removed. Jump to the beginning of main processing after output processing.

If there is no mode change, S, MI61, 81
At 62, the photometry switch SWS and the photometry switch enable flag? AEAF control processing that determines the state with 5WSEN, displays the focal length with S and MI63 to M165, clears the display hold flag, and performs shutter-related control after loop extraction processing if predetermined conditions are met. branch into.

Branching to AEAF control processing occurs when the photometry switch is turned on.
This is a case where the camera is on, and the stored switch data of SWS, SWR, position E, and WIDE are all OFF, and the mode setting is such that photography is possible.

In other words, branching to the AEAF control process occurs when the SWS
This only applies when the switch changes from FF to ON; if the zoom lever is being operated, etc., the main process continues without branching.

In S, MI66, charging control processing of the strobe circuit is executed, and in S, MI67 to MI71, display switching processing is executed.

If display hold is requested, for example, in the main process after zoom processing, which will be described later, it is determined whether one second has passed since the display timer was cleared.

Before the timer elapses for 1 second, the currently displayed display is held.

If display hold is not requested, or when the timer elapses for 1 second, if a display other than the number of sheets is being displayed, the number of sheets is displayed, and the display hold flag is set? W.A.
Clear ITD.

In this way, the film number display is displayed preferentially over other displays, except when switched from time to time.

Then, after stopping the 125m5 processing at S, MI72,
At 50M173, charging prohibition time processing is called, and after returning, the process jumps to main processing S and MI2 and continues processing.

This concludes the explanation of each step of the main processing, and then the flow branching from the main processing and the subroutines will be explained.

(Zoom Initialization Process) FIG. 16 is a flowchart of the zoom initialization process called at S and R33 of the reset process.

In this camera, the zoom code is a relative code as described above, so if the battery is removed and the memory contents are discarded, the camera itself will no longer be able to determine the current position of the photographic lens. The zoom initialization process is performed in such a case to partially pull back the photographing lens to the lock position.

First, the zoom code ZCODE is inputted from the conduction state of the brush slidingly in contact with the code plate at S and ZTl.

In S and ZI2 to 218, if the lens is not in the lock position, the motor is reversed at high speed, and if the lens is already in the lock position, the zoom motor is rotated forward at high speed for 100 m5, then reversed and pulled back to the lock position.

Then, at S and ZI9, the position code PO8 is set to 0, the lock position flag is set to 1, and the macro position flag is set to O, and the process returns to the called position.

Next, zooming-related processing, zoom reversal processing, forward rotation processing, telephoto and wide movement processing will be explained, but before that, code check processing that is frequently called within these processing will be explained.

(Code check processing) FIGS. 17 and 18 show that position code PO8,
Day vision code DIV, zoom code change prediction values ZCFOW, ZCRI! This is a process to determine V.

However, since a portion of the zoom code is a relative code, it is not possible to specify the position code and division code corresponding to the focal length of the lens from only the statically detected zoom code.

Therefore, in this code check process, while dynamically detecting changes in the zoom code from the lock position (ZCODE=2.> where the zoom code is an absolute code), position code PO8 and day vision code DIV stored in memory are are being rewritten one after another.

When entering this process, first press the lock switch with S and CK1.
4- -(Capital)- LOCK, macro switch MCRO, wide switch W
IDE, tele switch position E, speed selection switch Z
Each data of MHL is input. These switch data are used after a return when a code check process is called in a tele movement process, a wide movement process, etc., which will be described later.

For S, CK2 to CK5, when the position code indicates wide end (PO2-4) or tele end (PO2-4),
These are forcibly set to codes indicating the zoom range (PO2-4) and the macro position side CPO3=4> from the telephoto end. As described above, the position code PO8 at the tele end and wide end has no width, so it immediately takes on another value when the zoom motor is moving.

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

If there is a change, different processes are executed depending on the direction of the rotational force of the zoom motor. If the motor rotates forward,
Proceeds from S, CK8 to S, C) f9, and in case of reverse, proceeds to S, CK25 in FIG. 18.

Let's start with the case of stopped rotation.

Note that, due to the processing of S and CK2 to CK5, the value of pos becomes either 0 or 24.

When the lens is closer to the lock position than the wide end (pos
=o), until the ZCI terminal of the brush is turned ON, that is, until the wide end is reached, the process returns directly to the called step from 10 in S and C.

If ZCI becomes a leaf, P at S, CK11
Set O8 and IJ DIV to 1, and if the zoom motor is rotating in the normal direction, the zoom code value that will be taken after the next change (predicted change value in the normal direction of the zoom code) Z
Set CFOW to 4 and return.

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

When the lens is in the zoom range (pos=2), S,
Proceeding from CK12 to S and CK13, it is determined whether the division code DIV is less than 2. If it is 2 or more, it is determined at S and CK14 whether the state of the ZC2 terminal has reached the tele end. do.

As shown in FIG. 7, the ZC2 terminal becomes 0 on the lock position side from the wide end and between the zoom range and the macro position. Therefore, theoretically, ZC2 ends at PO2-4.
It is inconceivable that the value becomes 0, and the telephoto end can be detected even without the S and CK13 steps.

However, due to manufacturing errors in the code board, it is possible that the region where ZC2 is 0 on the wide end side and the region where ZCI is 0 partially overlap.

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

When the tele end is detected, S, CK15. At CK16, set POS to 3, DIV to EH, and set LC
Change the D display to the telephoto end focal length display (70 mm) and return. Note that when entering this flow, the focal length is necessarily displayed on the LCD display.

If the telephoto end has not been reached, S, CK17. CKl
In B, assuming ZC2 as 1, zoom code ZCOD
E and the predicted change value ZCFOW are compared. If these are equal, at S, CK19 to CK22, the division code is counted up, a new predicted change value is set, and the display keep flag is set? KPLCD is 0 (
If the display change is t'11), a new focal length corresponding to IV is displayed and the process returns.

S, CK9. If both judgments at CK12 are negative,
In other words, if the lens is closer to the macro position than the telephoto end (
PO2-4) uses S and CK23 to determine whether the ZCO terminal is 0 or not, and if it is 0, S and CK24 set the macro position flag? In addition to setting MCRO to 1, the macro request flag? Clear RQMCRO and return.

If the motor is in reverse rotation, S, CK2 in Figure 18
Jump to step 5 to proceed with the process.

2 of the zoom code ZCODH is an absolute code and means that the lens is in the locked position. In this case,
Branching from S, CK25, the brake of the zoom motor is applied at S, CK2B. And S, CK27. C
K28 sets POS to 0 and sets the lock position flag?
Turn LOCK and jump the stack process to the top of the main process using the lever.

When the lens is closer to the macro position than the telephoto end (P-33)
-34=03=4) 2 proceeds to S, CK29 or S, CK30, and returns to the called step as long as the zC1 terminal is 1.

If the ZCI terminal is 0, it is assumed that the lens has entered the zoom range, and POS and DIV, as well as a change prediction value in the reverse direction ZCREV, are set. If display change is permitted in S, CK32, S, CK33 is set. Returns the focal length display as a new value (65 mm).

Next, if POS is not 4, the processing is divided into the case of PO2-4 and the case of pos=o in S, CK34, and when the lens is at the lock position side from the wide end (pos
s=.

) is returned as is.

When the lens is in the zoom range (PO2-4), S,
The day vision code is B for CK35 to CK39)
It is determined whether the ZC2 terminal is 0N (0) on the condition that it is below I, and if it is 0, it is determined that it is closer to the lock position than the wide end, and the POS is set to 0, and the display is changed. If permitted, the focal pressure 1114 display will be changed to a new value (3
5mm) and return. The determination of S and CK35 takes into consideration the manufacturing error of the code plate, as in the case of S and CK13 described above.=35-.

In S, CK40, and CK41, the ZC2 terminal is regarded as 1, 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, S, CK4
In steps 2 to CK45, the day vision code is subtracted by 1 and new predicted change values ZCFOW and ZCREV are set, and if 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 settings are all set to 0FF of terminals ZC0, 1, and 2.
It is detected by the change from (1) to 0N (0),
This prevents detection errors due to floating brushes and prevents the zoom motor from stopping at a stop-prohibited position.

(Zoom reversal processing) Figure 19 shows main processing S, M122. M142. M.I.
50 is a flowchart showing zoom reversal processing branching from 50 and 8154. This process involves pulling the photographic lens into the lock position and returning it from the macro position to the zoom range. Note that when stopping within the zoom range, a normal rotation operation is included to eliminate the influence of backlash.

Hereinafter, zoom-related processing will be explained with reference to the operation diagram shown in FIG. 20.

When branching to this flow, first the macro teleshift flag is set in S, ZRl, and ZR2. MTSrFT and macro position flag? Clears MCRO and reverses the zoom motor at high speed.

Is there a display keep flag on S and ZR3? KPLCD is set to 1 and changes in focal length display are prohibited, S, ZR4, ZR5
Then, if the lens is closer to the macro position than the telephoto end, the code check is repeated.

If the lens is set closer to the zoom range than the telephoto end,
Alternatively, if the zoom range is entered while repeating the determination of S and ZR5, 0N10FF of the lock switch LOCK is determined by S and ZR6.

If the lock switch is ON, the display keep flag on S and ZR7? Clear KPLCD. Then, in S and ZR8 to ZR13, the motor is reversed 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 process jumps to the beginning of the main process to continue the process. The movement in this case is indicated by the symbol a in FIG.

If the lock switch is turned OFF before the zoom motor crosses the wide end due to reversal of the zoom motor, S, ZR14 to Z
At R23, when the switch is turned OFF, the lens is rotated 70 m5 in the reverse direction and 50 m5 in the forward direction, and if the lens is in the zoom range, it is stopped as it is (the movement already indicated by the numbers in Fig. 20).
.

If the lens is closer to the lock position than the wide end even after forward rotation, the motor continues to rotate forward until the wide end, extends to the wide end, and then stops the motor (movement indicated by symbol C in Figure 20). . In either case, the focal length is displayed, the process jumps to the beginning of the main process, and the process continues.

On the other hand, if the lock switch is OFF L from the beginning, the process proceeds from S, ZR6 to S, ZR24, and if the wide switch is ON, the process jumps directly to the rJPWIDEJ terminal for wide movement processing, which will be described later. I can continue. If this is not the case, after 50m5 has elapsed since the zoom range has been reached in S, ZR25 to ZR30, the motor is rotated forward at high speed, the lens is set to the telephoto end, and the main processing is performed (indicated by reference numeral d in Fig. 20). movement).

In zoom reversal processing or wide movement processing
When the sTOPWDJ terminal enters this reversal process, in order to eliminate backlash, the motor is rotated forward for 50 m5 after stopping the reverse rotation, and then the motor is stopped. Therefore, if changing the focal length display is not prohibited, a short focal length will be displayed when the camera enters the DTV area on the wide side, and a long focal length will be displayed when it is reversed and enters the DIV area on the tele side. It may be possible to switch. Such a change in display may give the user the impression that the camera has erroneously moved to the telephoto side just before stopping, even though the focal length is shifted to the wide side. So, what about the display keep flag in this case? The configuration is such that when the KPL CD is set up, changes in the display are temporarily prohibited, and changes are permitted when the zoom motor stops.

-Problem- (Zoom normal rotation processing) Figure 21 shows main processing S, MT29. 12 is a flowchart showing normal zoom processing branching from the old 36; This process moves the photographic lens from the lock position to the wide end or from the zoom range to the macro position.

When the zoom motor starts to rotate forward, first, S, ZFl,
Lock position flag in ZF2? Clear LOCK and rotate the zoom motor forward at high speed. S, ZF3~ZF6
Now, after confirming that the lens is closer to the zoom range than the wide end, if there is no macro request, the camera stops and jumps to main processing. This is a process of moving the lens from the lock position to the wide end when the main switch is turned on, as indicated by the symbol e in FIG.

If there is a macro request, wait for the lens to pass the tele end of the zoom range with the lock switch turned OFF at S, ZF7 to ZF9, and stop the motor at S and ZFlo if the lock switch is turned ON. to jump to main processing. When the lens passes the telephoto end, S, ZF11
~ Macro position flag in ZF13? After waiting for MCRO to rise, the motor is stopped (movement indicated by symbol f in FIG. 20), and the process is proceeded with the main process.

This is the main switch ON (lock switch 0FF)
This is the behavior when you press the macro button in the state.

-1. As shown in the above-mentioned zoom motor reverse rotation and forward rotation processing, all lens drives by operations using the main switch or the macro button 16 are performed at high speed.

(Tele Movement Process) FIG. 22 is a flowchart showing the tele movement process that branches from the main process S, M+40.

This process is executed by turning on the teleswitch position E while the photographic lens is within the zoom range. This process is similar to the normal zoom rotation processing described above in that the zoom motor is rotated in the normal direction to move the photographing lens, but the difference is that the zooming speed can be switched between high and low speeds.

When entering tele-movement processing, first the ZM motor is rotated forward at high speed at S and ZTl, and the timer for speed switching is cleared and started at S and ZT2.

For S, ZT3 to ZTIO, the tele switch must be turned on and the lens must not have reached the tele end (pos≠
3) On the condition that the lock switch is OFF, the motor is driven at high speed for 30 m5 at startup, and after 30 m5 has passed, the motor is rotated forward by switching between high speed and low speed according to the selection of the speed changeover switch.

When the teleswitch position E is turned off in the zoom range, the operation is as indicated by the symbol g in FIG. 20. Further, the operation when the telephoto end is reached is indicated by a symbol.

If any of the conditions listed in -1- are no longer satisfied,
Stop the motor with S and ZTll and proceed to the beginning of the main process.

(Wide Movement Process) FIG. 23 is a flowchart showing the zoom wide movement process that branches from the main process S and MI46.

This process is executed by turning on the zoom wide switch WIDE while the taking lens is in the zoom range, and is similar to the zoom reversing process described above in that the taking lens is moved in the retracted direction, but the zooming speed is The ability to switch is common to tele-movement processing.

When entering wide movement processing, first, the zoom motor is reversed at high speed in S and ZW1, and the timer is cleared and started in S and ZW2. S of the zoom reversal process mentioned above
, E25, the processes following S and ZW2 are common.

For S, ZW3 to ZWIO, the 30m5 at startup is on the condition that the wide switch is ONL, the lens is not in the lock position from the wide end (pos≠0), and the lock switch is OFF. Drive at high speed,
After 30 m5 has passed, the motor is reversed by switching between high speed and low speed according to the selection of the speed changeover switch.

When the wide switch WIDE is turned off, S,
After setting the motor rotation to high speed in ZWll, the process branches to S and ZR14 of zoom reversal processing, and processing for removing the influence of backlash is executed (second
(movement indicated by code i in Figure 0).

If the wide switch WIDE is turned OFF L in the zoom range, and when the above-mentioned 70m5 forward rotation and 50m5 reverse rotation are completed, it is closer to the lock position than the wide end, as shown in Fig. 20? :1 knee 1; As shown in j, extend it to the wide end and stop the rhythm motor.

If the lens is in the lock position from the wide end,
After setting the motor to high speed with S and ZWl2, press S.

After waiting 50 m5 at ZW13 to ZW17, the zoom motor is reversed, the lens is set to the wide end while removing backlash, and the motor is stopped (movement indicated by the symbol in FIG. 20), and the process jumps to the main processing.

When the lock switch is turned on, the motor is stopped at S and ZW18, and the main processing begins. In this case, the main process branches to the zoom reversal process and the lens is pulled back to the lock position.

(Lock Processing) FIG. 24 shows the flow of lock processing branching from main processing S and MI24. This process is branched and executed when the lock switch is turned on and the photographing lens is stored in the lock position.When this process is started, the loading end flag is displayed at S, LK1 to LK4? Depending on the state of LDEND, the number of sheets is displayed on the LCD display or turned off, and the mode is returned to its initial value.

S, 'LK5 to LK13 loop, make sure the rewind switch REW is 0FFL, and the back cover switch BAC.
It is executed repeatedly at intervals of 125 m5 on the condition that K is OFF or ON, but loading has finished, and the lock switch is ONL.

8, LK12. In LK13, main processing S, MI7
Charging prohibition time processing similar to 3 is performed.

When the rewind switch is ONL, the process branches to the above-mentioned rewind process from S and LK6.

When the back cover is closed and loading has finished, a loop is formed by skipping S, LK9 LKIO, and when the back cover is opened, the loading completion flag is cleared and the number of sheets display is turned off. be done. When the back cover is closed in the next loop, the process branches to the above-mentioned loading process from S and LK8.

When the lock switch LOCK is turned off, S,
Charging start flag at LK14 and LK15? CHGST
and display hold flag? WAITD is set to 1 and the process jumps to main.

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

[Brief explanation of the drawing]

The drawing shows a camera equipped with camera lens position detection according to the present invention. 1 to 3 show the external appearance of the camera, with FIG. 1 being a plan view, FIG. 2 being a front view, and FIG. 3 being a rear view. Figure 4 is a block diagram of the control circuit, Figure 5 is an explanatory diagram of the contact configuration of the zoom switch, Figure 6 is a block diagram of the zoom motor control system, Figure 7 is a developed diagram of the code plate, and the code plate and each code. FIG. 8 is an explanatory diagram of mode setting, and FIG. 9 is an explanatory diagram of LCD display segments. 10 to 19 and 21 to 24 are flowcharts showing the functions of the electric zoom device of this embodiment.
The figure shows the main process, Figure 12 shows the loop extraction process, and the first
Figure 6 shows the zoom initialization process, Figures 17 and 18 show the code check process, Figure 19 shows the zoom reversal process, and Figure 21 shows the zoom reversal process.
The figure shows zoom normal rotation processing, Fig. 22 shows tele movement processing, and Fig. 23 shows zoom normal rotation processing.
The figure omits the wide movement process, and FIG. 24 omits the lock process. FIG. 20 is a diagram for explaining the zooming operation.

Claims (1)

[Scope of Claims] A code plate having a pattern of conductive portions and non-conductive portions to divide the zoom lens position into a plurality of regions, and a conductive portion of the code plate that moves relatively while slidingly contacting the code plate. A camera lens that is equipped with a plurality of brushes that detect contact or non-contact, and a zoom motor for driving the lens that is controlled based on signals from the brushes, and a predetermined area is a prohibited area for the lens to stop. What is claimed is: 1. A position detecting device for a camera, wherein the end point of the prohibited stop area is detected at a point where the brush switches from a non-conducting portion to a conducting portion of the code plate.