JP2623631C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a subject distance detection device in a camera. B. 2. Description of the Related Art An active type distance measuring device has been conventionally used as a distance measuring device for a camera.
. This emits a parallel beam of light from the light source provided in the camera parallel to the camera optical axis.
The image of the irradiation spot of the light beam on the subject is placed on the side of the light source.
It is formed so as to straddle two light receiving elements, and according to the output ratio of these two light receiving elements
This is a method for detecting the subject distance. When performing distance measurement with this active method,
The image of the spot on the subject formed by the light from the element is received depending on the distance
Moving on the surface, and the output ratio of the two light receiving elements changes with the subject distance.
The distance to the subject is measured by the output ratio of the image of
Is wide, the moving distance of the image is also large. Therefore, the light emitting element and the receiving
If you try to measure the distance between 0 and ∞ subjects with the optical element fixed, light is received at the short distance side
There is a case where no image is formed on the element. For example, FIG. 21 shows a conventional distance measuring system.
Here is an example. Due to the reflected light from the subject of the light beam emitted from the light emitting element LED
The image I moves on the light receiving elements SPC1 and SPC2 according to the subject distances S1 to S5.
Therefore, the output ratio of SPC2 and SPC1 changes according to the movement of the image. That is,
Since the output ratio between SPC2 and SPC1 changes depending on the distance, this SPC2 / SPC1
The relationship between the output ratio of PC1 and the distance is represented by a relationship curve as shown in FIG. This
Is constant regardless of the reflectance of the subject, so by measuring this ratio
, The distance to the subject can be measured. However, as can be seen from FIG.
When the subject distance becomes short, such as S4 or S5, the reflected light from the subject
The image I is shifted rightward and hardly forms an image on the SPC1 surface, but forms an image only on the SPC2.
As a result, the ratio of SPC2 / SPC1 does not change with distance, as shown in FIG.
The distance resolution decreases and the distance measurement becomes impossible
Problem occurs. C. Problem to be Solved by the Invention The present invention is based on an active method, in which the distance to a subject is determined by the output ratio of two light receiving elements.
It is intended to measure the separation with a high accuracy over a wide area from a short distance to a long distance. D. Means for Solving the Problems In order to achieve the above object, according to the present invention as set forth in claim 1, light is applied to an object field.
The distance to the subject by calculating the distance from the subject by receiving reflected light from the subject.
A distance device that projects light in different directions of the scene at different timings
A distance measuring device capable of measuring a plurality of areas in a field of view with a first region.
Receiving the light projected onto the area and reflected by the subject within a first distance range within the first area
A first light receiving means, and a second distance range projected on the first area and within the first area.
While receiving the light reflected by the subject in the surroundings, the light reflected on the second area is projected onto the second area.
Second light receiving means for receiving light reflected by a subject in the area, and the first light receiving means
Object distance within a first distance range within the first area according to the light reception result of
A first distance measurement result indicating the separation is obtained, and the first distance measurement result is determined according to the light reception result by the second light receiving unit.
A second distance measurement result representing a subject distance in the second area, and a second distance measurement result in the first area.
An operator for obtaining a third distance measurement result representing a subject distance within the second distance range
It is characterized by having a step. Further, in the present invention according to claim 2, further, a light is projected onto the first area.
(1) having a first light projecting means and a second light projecting means for projecting light to the second area
It is characterized by. Further, in the present invention according to claim 3, the first light receiving means is provided with the first light emitting means.
Means for receiving light projected onto the first area at a first timing, and receiving the second light receiving means;
The stage receives the light projected by the second light projecting means to the second area at the second timing.
And the light emitted by the first light emitting means to the first area at the third timing.
Is received. On the other hand, according to the present invention as set forth in claim 4, the first light receiving means is provided with a first light receiving element.
A second light receiving element, wherein the second light receiving means is provided with the second light receiving element. element And the third
And a light receiving element. E. Operation FIG. 6 shows a principle diagram for explaining the distance measuring operation of the present invention, and FIG.
Will be described. The light receiving elements are SPC1, SPC2, and SPC3, and the light emitting element L
The ED image is projected onto the subject, and the reflected light of the LED light from the subject is received by three light receiving elements
And three light receiving elements SPC1, which receive reflected light of the LED light.
From the detection output of SPC2 and SPC3, the ratio of the output of SPC2 / SPC1 to SPC3 /
The output ratio of SPC2 is determined. The image of the subject must be
Of the light receiving elements, so that either ratio of the distance to the second
The distances S1, S2 and S3 are in the proportional range shown in FIG.
In this case, the distance is measured by the light receiving element pair SPC1 and SPC2, and the short distance S
In S4 and S5, the distance can be measured by the other light receiving element pairs SPC2 and SPC3.
You. Therefore, in a distance measuring device capable of measuring the distance of a plurality of regions in the object scene,
The distance from the area different from the area measured by the light receiving element pairs SPC1 and SPC2 is
By using a pair of light receiving elements SPC2 and SPC3 prepared to receive the emitted light.
Thus, distance measurement in a different distance range (short distance range) becomes possible. F. Embodiment FIG. 1 shows a schematic configuration of a distance measuring system according to the present embodiment. FIG.
In the method of measuring the distance of one point by three light receiving elements, five points on the screen shown in FIG.
This is to measure the distance of the subject in the distance measurement areas (AF1 to AF5). In FIG. 1, LEDs 1 to 5 are light emitting elements, and are arranged in a row at right angles to the optical axis of the camera.
Are arranged so that the focal plane is located on the row of these light emitting elements.
Then, the images of the light emitting elements LED1 to LED5 are projected on the subject. AF1 to AF5
Are the images of the light-emitting elements on the subject, and the range of this image corresponds to the distance measurement area in the object scene.
Become. The image of the light emitting element on the subject is received by the light receiving elements SPC1 to SPC1 through the lens l2.
It is formed on the array of PC6. For example, in the figure, the hatched portion A is the light emitting element LE
D1 is an image of the image on the object by the lens l2. In the figure, it is divided into SPC1 and SPC2.
It is formed. Distance measurement using a pair of adjacent light receiving elements
This is the same as the active method, so that distance measurement can be performed at five locations on the shooting screen.
Done. In this embodiment, the closest distance is selected from the five distance measurement results, and the camera is focused on the closest distance. How to use the plurality of distance measurement results
It is optional. When measuring the distance, the light emitting elements are turned on sequentially, and the light receiving element corresponding to the light emitting element to be turned on
Measures the distance of the light emitting element LED1 by SPC1 and SPC2, and
Distance measurement is performed on the slave LED 2 by SPC2 and SPC3. Similarly, LE
D3, LED4, and LED5 are also measured with two light receiving elements. above
In this case, the selection of the light receiving element set is a selection when the distance to the subject is long.
For the LED3, the distance is measured again by the short-distance light receiving element set SPC4, SPC5.
The output ratio of the light receiving element is in the proportional range even when the distance to the subject is short
To do. A feature of the present invention is that three or more light receiving elements are arranged corresponding to one light emitting element.
In this embodiment, the present invention is applied to the center AF3 of a plurality of ranging areas.
Distance measurement. That is, for the reflected light from the image of the light emitting element LED3 on the subject,
The distance is measured using the three outputs of the light receiving elements SPC3, SPC4, and SPC5. Suffered
When the object is farther than a certain distance, the reflected light from the subject of the radiated light of the LED 3 is SP
The light enters C3 and SPC4, and the distance is obtained from the output ratio of SPC3 and SPC4. Some
When the distance from the subject is short, the reflected light from the subject comes closer to the SPC 5 on the right.
Thus, the distance is determined by the output ratio between SPC4 and SPC5. Just in the center of the screen
When performing distance measurement to a short distance, when the subject is in a short distance,
Because it seems to cover the body, the short distance measurement measures the distance in the center AF area AF3
Thus, it can be determined that focusing operation can be sufficiently performed. FIG. 2 shows an outline of the circuit configuration of the above embodiment of the present invention. LED1 to LED5
It is a light emitting element such as a light emitting diode of a light source. SPC1 to SPC6 are light receiving elements.
You. Tr2 to Tr6 are driving transistors for lighting the light emitting elements LED1 to LED5.
MPX1 is a multiplexer for sequentially lighting the light emitting elements LED1 to LED5.
Kusa. MPX2 and MPX3 are also multiplexers, and MPX2 has an input terminal a
, B, c, d, and e receive signals obtained by logarithmically converting the outputs of the light receiving elements SPC1 to SPC5.
Is forced. MPX3 is a logarithmic conversion of the output of SPC2 except for the light receiving element SPC1.
The output is input to the uppermost input terminal a ′, and signals obtained by logarithmically converting the outputs of SPC3 to SPC6 are input to the input terminals b ′ to e ′. ANC
1 to ANC6 are logarithmic conversion amplifiers. Clock pulse from control circuit not shown
Accordingly, the input terminals of the multiplexers MPX1 to MPX3 are sequentially selected synchronously and sequentially,
At the timing when the light emitting element LED5 is turned on, the multiplexers MPX2 and MPX2
The output terminals a and a 'of MPX3 are selected, and the logarithmic change of the outputs of SPC1 and SPC2 is performed.
The converted signal is input to the differential amplifier DIF, and the difference between the two signals is output. Of this difference
Since the signal is a logarithmic difference, it is a ratio of the outputs of the light receiving elements SPC1 and SPC2.
Are input to the comparators c1 to c8. Each of the comparators c1 to c8 has
A reference voltage obtained from each point on the voltage dividing resistor R through which a constant current flows is applied.
The outputs of the differential amplifier DIF are classified into eight stages. This operation is LED sequentially
4, LED3 to LED1 are turned on, and the AF5 to
The distance of the AF1 portion is detected. After completing the above operations, the control circuit
When the multiplexer MPX1 is driven to turn on the LED3,
Select the input terminals d and d 'of the lexers MPX2 and MPX3 and receive light in the same manner as described above.
The output ratios of the elements SPC4 and SPC5 are classified and taken out. The control circuit is
When all the outputs of the radiators c1 to c8 are at the high level, it is determined that the distance cannot be measured at a short distance.
And other comparators, depending on how many comparators have high output.
, Distance is detected. The feature of this embodiment is that the distance measurement operation is repeated twice,
In FIG. 1, the distances of the respective portions AF1 to AF5 on the object are measured, and the second measurement is performed.
In operation, the central portion AF3 is measured again using the adjacent light receiving element. First action
When the distance at the center is determined by the above, the second operation is unnecessary, but the first operation is performed.
Whether to perform the second operation depending on whether the distance of the central part is determined by the operation
Rather than deciding whether to do this, it is easier to make the program operate twice.
Also, the measurement at the short distance is performed only for the center of the screen,
When the subject is at a short distance, the subject covers the entire screen.
This is because the object is always located. The summary has been described above, and the details of the above embodiment will be further described below. First
First, details of the distance measurement circuit AF, which is a main part of the present invention, and the distance measurement area occupied in the shooting screen
A description will be given of the photometric range for controlling the area and the exposure. FIG. 3 shows a distance measurement area and a photometry range occupying the photographing screen. Explaining with reference to the figure, the outermost frame FLM indicates the shooting screen.
5, five AF1 to AF5 indicated by solid lines indicate a distance measurement area, and four A's indicated by dotted lines
E1 to AE4 indicate photometric ranges. As described above, in the present embodiment, multipoint ranging,
Although point metering is performed, the method for selecting the distance measurement value is, in principle, the closest to the camera.
The main subject, and includes the distance measurement area in the photometry ranges AE1 to AE4.
One of the photometric values in the photometric ranges AE1 to AE3 is defined as the photometric value of the main subject, and the photometric range AE
4 is compared with the photometry value of the main subject to detect whether the subject is in a backlight state or not.
I have. Within the photometric range AE1 to AE3. The photometry ranges AE1 and AE3 are respectively the distance measurement areas (A
F1, AF2), (AF4, AF5), and the light metering range AE2
Includes only the distance measurement area AF3. Then, the photometry range AE2 is measured.
Compared to the ranges AE1 and AE2, the vertical configuration and arrangement are as follows.
It depends on the reason. I) To make the area equal to the area of the other photometry range, and thereby, due to the difference in the area
The adjustment of the photometric output is omitted. II) The main subject is often located at the center, in which case the main subject is
This is because there are many configurations. The distance measurement areas AF1 to AF5 are 1 m to ∞, and the distance measurement area AF3 is 0.5 m to 1 m.
Is measured separately. The reason that the distance range for measuring only the center is wide
(0.5m to 1m), the main subject becomes larger and spreads over the entire screen.
This is because the main subject is hardly removed by measuring the distance of only the portion. In FIG. 2, MPX1 is a signal OT1 [from a microcomputer μc (see FIG. 4).
Signals corresponding to the distance measurement areas AF1 to AF5].
Any one of the output terminals 1 to 5 so as to select the distance area AF and the LED to emit light.
One of the multiplexers outputs the "H" level. MPX2, MPX3
In response to the signal OT1 from the microcomputer μc, the distance measurement area AF and the light receiving element shown in Table 1 are displayed.
One of the signals input from each SPC is selected so that the relationship with the
It is a multiplexer that outputs to the width unit DIF. C2 is energy for the light emitting element LED
This is a condenser for supplying the power. AN1 to AN5 and Tr2 to Tr6 convert light emitting elements LED1 to LED5 corresponding to the distance measurement areas AF1 to AF5 from the MPX1.
And an AND circuit for emitting light in response to the signal "H" and the distance measurement start signal AFS.
It is a ranista. ANC1 to ANC6 emit light of the light emitting element reflected from the subject.
An analog circuit for extraction, a multiplexer MPX2 as a logarithmically compressed signal
, MPX3. The differential amplifier DIF includes multiplexers MPX2 and MPX.
3 is the circuit that takes the difference between the outputs from
The ratio of the input signal of the light receiving element is taken). c1 to c8 are output levels of the differential amplifier
The latch circuit connected to the comparator detects the AF start signal.
The output of the comparator is latched by the signal of the circuit (delay) that provides
, To the selection circuits CH1 to CH8. Reference voltage of the comparators c1 to c8
Is formed by a constant current element I1 and a voltage dividing resistor of a known technique. In the present application, as shown in FIG. 1, five light emitting elements LED1 to LED5 and six
It is composed of optical elements SPC1 to SPC6. These light emitting elements LED, light receiving
Table 1 below shows the relationship between the combination of the elements SPC and the ranging area. In the distance measurement area AF3, the light emitting element uses the LED3, but the light receiving element uses the distance measurement.
Unlike the case of the area AF3, it is possible to use SPC4 and SPC5 having the base lines apart from each other.
And, it measures closer distance. The distance measuring operation will be described. By the control signal sent from the OT1 terminal of the microcomputer μc
Then, the distances from AF1 to AF5 are sequentially measured by the combinations corresponding to Table 1 above. each
The detection signal of the light receiving element SPC obtained in the distance measurement area is logarithmically compressed by MPX to increase the differential signal.
Calculate the difference between two logarithmically compressed detection values (that is, the ratio of detection output) in the width unit DIF.
, And the calculated value is sent to and stored in the microcomputer μc. From the stored distance values
The value of the short distance is extracted, and the focusing operation is performed using the value. The details are described below.
. In the distance measurement of the distance measurement area AF3, the light receiving elements SP4 and SPC5 are insufficient.
When it is desired to measure a short distance, the light receiving elements SPC5 and SPC6 are used.
I just need to be. FIG. 4 shows an overall circuit block diagram of one embodiment of the present invention. In FIG.
The shutter of the camera used in the embodiment is a shutter dedicated to the aperture. μc
A microcomputer that performs the entire camera sequence and various operations
). The microcomputer μc is connected via a power supply E and a diode D1 for preventing reverse charging.
Power is supplied. C is a background condenser. AF
An active type distance measuring circuit that measures the distance to the subject. DX is a film
Film sensitivity reading to read the film sensitivity of the film with the sensitivity code
It is a taking circuit. BV is a photometric circuit that measures the brightness of the subject. Distance measuring circuit A
Distance measurement data from F, film sensitivity data of film sensitivity reading circuit DX and
The photometric data of the photometric circuit BV is transmitted from the selectors CH1 to CH8 to the shift register SR.
Is sent to the microcomputer μc. Description of distance measuring circuit AF and photometric circuit BV, and
The data transfer to the microcomputer μc will be described later. AE is an exposure control circuit.
The shutter is opened and closed according to the phase and number of pulses Φ1 and Φ2 from the icon μc.
Control. LE is a lens drive circuit, based on the distance measurement data, which is output from the microcomputer μc.
Controls lens extension and retraction by the phase and number of pulses Φ3 and Φ4
I do. MO is a one-frame winding circuit which controls film winding by signals M1 and M2 from the microcomputer μc. ST is an electronic flash device that controls charging from the microcomputer μc
In response to the signal CHC, light emission starts and stops, and light emission is performed by the light emission start signal X.
, And outputs a signal CHD indicating the state of charge of the capacitor C to the microcomputer μc. T
r1 supplies power to the distance measuring circuit AF, the film sensitivity reading circuit DX, and the photometric circuit BV.
It is a power supply transistor for supplying power. The microcomputer μc and other circuits
Powered directly from Xr is a crystal oscillator. The microcomputer μc clocks this
The microcontroller μc uses the clock sent from the crystal oscillator.
Two types of clocks obtained by dividing the clock can be used. LED is ready for shooting
Switch S1 is turned on, and the capacitor of the flash device ST
When the voltage does not reach the voltage, a warning is issued by light emission. Next, the switches will be described. S0 is a main switch of this circuit.
In response to the rise or fall of the signal due to ON or OFF of the switch S0,
The shot shot circuit OS1 outputs a pulse to the microcomputer, and the microcomputer μc receives the pulse.
Then, the interrupt ZNT0 is executed. S1 is O when the first step of the release button is pressed.
N is a shooting preparation switch. When this switch S1 is turned on, a one-shot circuit
A pulse is output from OS2, and the microcomputer μc executes an interrupt ZNT1 described later.
You. S2 is caused by pressing the release button in the second step (deeper than the first step).
Is turned on, and the microcomputer μc performs a shooting operation in response to the ON signal. S3 is a predetermined length
This is a one-frame switch that turns ON when the film is wound up.
Turns off when operation is performed. FIG. 5 shows a specific configuration of the photometric circuit BV. In FIG. 5, the light receiving element SPC
11 to SPC14 correspond to the photometric ranges AE1 to AE4 shown in FIG.
Table 2 below shows this relationship and the relationship between the signals input to the multiplexer MPX4 described later.
Show. The photometric circuits ANC11 to ANC14 output from the light receiving elements SPC11 to SPC14.
It is configured to process a force current and output a current corresponding to the brightness to the MPX4.
You. The photometric circuit ANC14 corresponds to the photometric range AE4, and the relationship is the photometric range AE4.
Since it is larger than 1 to AE3, current values for the same luminance are different. Photometry circuit ANC1
4, the currents for the same luminance are stored in the circuits ANC11 to ANC11 in the photometric ranges AE1 to AE3.
13 has been corrected inside the circuit. MPX4 is a microcomputer μ
c to select the outputs of the photometric circuits ANC11 to ANC14.
One of them is connected to a double integration A / D circuit DC · A / D shown below. A / D times of double integration
The circuit DC / A / D is a well-known circuit, and detailed illustration is omitted.
Briefly describing only, CHG indicates the start of A / D conversion from the microcomputer μc.
During the “H” level of the signal ADS, the capacitor (not shown) is charged and
When the A / D start signal goes low, the photometric circuit
A charge / discharge cycle controlled to perform discharge by a current corresponding to the brightness of ANCs 11 to 14
When the voltage of the capacitor drops to a predetermined voltage by discharging,
An "L" level A / D end signal is output. AND circuit AN11, counter C
NT is used to count the time during which the discharge is being performed.
After the reset signal ADS becomes “L”, the clock sent from the microcomputer μc is charged.
Until the discharge circuit CHG outputs the A / D end signal of “L” level, the counter C
NT counts. The brighter the time, the shorter the above time (counting
Clock number is small). The counter consists of 4 bits.
And outputs the respective outputs to the selection circuits CH1 to CH4. Next, the specific configuration of the selection circuits CH1 to CH8 shown in FIG.
FIG. 8 corresponds to the selection circuits CH1 to CH3.
The distance measurement signal, the photometry signal, and the DX signal (film sensitivity signal) are
Distance measurement control that inputs from the photometry circuit AE and the DX circuit DX and controls these signals respectively
Signal AFC, photometric control signal AEC, DX control signal DXC are input from microcomputer μc
Then, each measurement signal corresponding to each control signal is passed. Figure 9 shows the selection
The selector circuit CH4 and FIG. 10 correspond to the selector circuits CH5 to CH8, in which the three signals in FIG. No.
FIG. 11 shows the configuration of one of the shift registers (SR1 to SR8) SR1.
is there. In the order of latching and transferring the signal from the selection circuit CH1, one-shot
The operating circuit OS11 operates to generate one pulse. Then, the “H” level of this pulse
During this period, the AND circuit AN28 becomes active, and the signal of the selection circuit (CH1) is output.
Input to the D input terminal of the latch circuit DFF. The one-shot circuit OS11 “
During the “H” level period, a clock is input from the microcomputer μc,
In synchronization with the rise, the latch circuit DFF22 latches the signal from the selection circuit CH1.
Then, the signal is output from the output terminal Q. The pulse from the one-shot circuit OS11 is
Before the first pulse from the microcomputer μc falls, it disappears (falls).
It is designed to be. The microcomputer μc shifts the shift register in synchronization with the falling edge of the clock.
The data output from the star SR1 is taken. The shift register SR1 is the second
, The latch circuit DFF of the previous stage shift register SR2
21, and latches and outputs the output signal. The microcomputer μc sends eight clocks,
In synchronization with this, the shift registers SR1 to SR8 transfer the data of the selection circuits CH1 to CH8.
Output to the microcomputer μc in order. This is called a serious transfer (SIO). The operation of the electric block diagram of the camera constituted as described above is shown in FIG. 12 and thereafter. Ma
Explanation will be made based on the flowchart of the icon μc. Main switch SO of FIG.
Is operated, a pulse is output from the one-shot circuit OS1 to the interrupt terminal of the microcomputer μc.
It is output to ZNT0, and the microcomputer μc inputs this, and the
Perform an interrupt. The microcomputer μc determines whether the switch S0 is turned on or not.
Is detected based on the level of the input terminal I0, and when it is turned on (I0
= “L”), assuming that shooting is to be performed, the output terminal and flag are initially set, and shooting is performed.
The interrupt INT1 by the shadow preparation switch S1 is permitted, and the charge control of the electronic flash device is performed.
($ 5-20). The charge control subroutine is shown in FIG.
Whether or not the electronic flash device ST is fully charged is detected by a signal CHD, and charging is completed.
If not (CHD = “L”), the boost control signal (CHC) is set to “H” level.
To start boosting (# 205, 210). Next, switch S1 is turned on.
It is detected whether or not the terminal OT3 is turned on (I3 = “L”), and the terminal OT3 is set to “H” level to indicate an uncharged state, and the LED (
(Red) and the process returns to step # 205 (# 215, 220). Of this LED
The display is enabled in step # 140 described later, and this interrupt ZNT
It does not occur at 0. When the shooting preparation switch S1 is OFF (I3 = “H”), L
In order to turn off the ED, the terminal OT3 is set to the “L” level, and the process proceeds to Step # 205 (
# 265, 217). On the other hand, charging is completed in step # 205 (or
, Charging is completed) (CHD = “H”), the boost control signal (HC) is set to “L”.
Level is stopped (# 225), and the shooting preparation switch S1 is turned on.
If it is (IT3 = “L”), the LED is turned off (OT3 = “L”) and return
Yes (# 230, 235). In step # 230, the shooting preparation switch S1
Returns immediately when is OFF (# 230). Returning to FIG. 12, control of charging
Is completed, the microcomputer μc turns off the power supply transistor (OT4 = “L”).
And stop (# 25). Stopping here means stopping the clock as well.
The clock is restarted by an interrupt. In step # 5
When the main switch S0 is turned off, the interruption by the photographing preparation switch S1 is performed.
Prohibition, and proceeds to step # 25 to turn off the power supply transistor Tr1 (OT
4 = “L”) and stop. Next, the interruption ZNT1 by the shooting preparation switch S1 will be described.
When the switch S1 is turned on, the one-shot circuit OS2 responds to this signal to
Then, the microcomputer μc inputs this and executes the interrupt ZNT1. First, the microcomputer μc stops boosting of the electronic flash device (CHC = “L”) and
To stabilize the source voltage, turn on the power supply transistor Tr1 (OT4 = “H”)
Then, power is supplied to each circuit (# 40). And when the ranging and photometry circuits are in a stable state
Wait for a while ($ 45). The microcomputer μc uses a clock for execution processing at a low speed.
Switch to high-speed mode to reduce the time required for data processing, especially for data transfer.
I have to. Before switching to the high-speed clock, the microcomputer μc operates at the low-speed clock.
moving. Next, A / D conversion of ranging and photometry is repeated, and ranging is performed for five ranging areas.
Data and photometric data of four ranging areas are obtained (# 55- # 95). The control of the A / D conversion of the distance measurement and the photometry is described with reference to the flowcharts shown in FIGS. 14 and 15, respectively.
It will be described in the light of the above. FIG. 14 shows a flowchart of the operation for measuring (detecting) the distance in the distance measurement area AF1.
. The distance measuring operation will be described with reference to this flowchart.
(Indicating a hexadecimal number), and designates to measure the distance in the distance measuring area AF1.
($ 305). Then, the ranging start signal AFS is set to the “H” level, and FIG.
The infrared LED 1 transfers the energy of the capacitor C2 through the AND circuit AN5.
To emit light. The infrared light emitted and reflected by the subject is received by the light receiving element SPC
1, input to SPC2, multiplexer MPX2, differential amplifier DIFAMP
Are compared by the comparators c1 to c8, and the distance measurement data is latched by the latch circuit.
Is touched. The microcomputer μc waits for this time (# 315) and outputs the distance measurement control signal AFC.
Set to “H” level to cause the selection circuits CH1 to CH8 to select the distance measurement signal,
The signal is latched by performing the “H” level serial data transfer.
At the same time, the microcomputer μc reads the distance measurement data, and the microcomputer μc records this signal.
Remember ($ 320-330). Then, the distance measurement start signal A at the "H" level is set.
FS, ranging control signal AFC, and latch signal are all set to “L” level,
Return (# 335-345). The same applies to the ranging operation in other ranging areas.
The difference is that the signal output from the terminal OT1 is different depending on the ranging area.
This is as previously shown. Next, A / D conversion of the output from the photometric circuit and acquisition of the A / D converted data
The control of the embedding will be described with reference to the flowchart shown in FIG. Microcomputer
μc outputs a signal indicating the photometry range from the terminal OT2 (# 405). Fig. 5
In the optical circuit BV, the multiplexer MPX4 outputs the output of the light receiving element SPC11.
Is connected to a double integration A / D conversion circuit DC · A / D. The microcomputer μc then switches to “H”
A / D conversion start signal ADS of a level is output, and the charge / discharge circuit CHG responds to this.
In response, the microcomputer μc starts charging the capacitor (not shown) as described above.
After waiting for the time required for this charging, the A / D conversion start signal ADS is set to the "L" level.
(# 410-420). As a result, the charging / discharging circuit CHG
From the capacitor, discharge is started according to the photometric output. The microcomputer μc starts outputting the clock CLK2 and indicates the end of A / D conversion from the double integration circuit DC A / D.
Waits for the signal ADE to be input, and when this signal is input, the output of the clock CLK2 stops.
Stop (# 425-435). Next, the photometry control signal BVC is set to the “H” level,
The signal is set to “H” level, the serial transfer control SI0 is performed, and the photometric data is
Enter ($ 440-450). Then, the signals LCH,
The BVC is set to the “L” level, and the routine returns. A / D conversion and other photometry ranges
And the control of the input of the data to the microcomputer μc is the same.
The point is that the data of the signal output from the OT2 differs depending on the photometry range. Here, the reason why distance measurement and photometry are performed alternately will be described.
In FIG. 2, the energy of the LED is supplied from the capacitor C2 and
After the LED emits light, it takes time to charge this capacitor.
Yes, if the distance measurement is performed before the charging is performed
No light emission is performed, and the range that can be measured is limited on the far side. This charge
A / D conversion of photometry and data input of microcomputer after measuring distance to save time
It is carried out. The time required for A / D conversion of this photometry and data input to the microcomputer is as follows:
About 10 msec, which is a sufficient time for charging the capacitor C2.
. It is conceivable that the distance measurement is performed five times in a row.
You have to wait for the time to power on (here 40 seconds in total), release time
When the love is long and you are shooting a moving subject, the image may be blurred or
There are problems such as a decrease in the number of shots. Referring back to FIG. 13, after the microcomputer μc completes the distance measurement in the distance measurement area AF5,
Wait for the charging of the circuit C2, and move the distance range of the distance measurement area AF3 to the near side.
Instead, the distance measurement (AF6) of the distance measurement area AF3 is performed. Now, the center area AF3
Although only the measurement is performed, this may be performed in the entire ranging area. However, in the entire ranging area
It takes time to perform distance measurement. In addition, a subject (human) at a short distance (0.5 to 1.5 m)
Considering the distance measurement of the object, the subject becomes relatively large, and the distance measurement shown in FIG.
Since the distance range is almost included, it is sufficient to measure the distance only in the central portion. Of this ranging
As described above, the light emitting element is LED3 and the light receiving elements are SPC4 and SPC5, as described above.
By using it, the base line length is lengthened and the near side is measured. The determination of the distance at this time is performed by processing within the microcomputer μc to which the signal of the distance measurement circuit is input to determine the distance measurement on the near side.
The distance in the area AF3 is determined. Next, a sequence for inputting the film sensitivity will be described with reference to FIG. Maiko
Μc sets the film sensitivity control signal DXC to the “H” level,
Then, a signal indicating the film sensitivity is output, and the latch signal LCH is set to “H” level.
Data of the film sensitivity is input by performing serial transfer SI0 (# 5
05-515). Then, a latch signal (LCH), a film sensitivity control signal DXC
Is set to the "L" level and the process returns (# 520, 525). After completing the data transfer control as described above, the microcomputer μc sets the processing clock to
Current consumption is reduced for low speed (# 110). And, for all ranging areas
A recent distance range is detected from the distance measurement data (# 115). Next, an exposure calculation for determining an exposure value is performed, and details thereof will be described with reference to FIG.
Then, based on the range closest to the camera, the photometric value BVSP of the subject
Is determined as shown in FIG. Recent range How to determine the spot metering value AF1 Bvsp = Bv1 AF2 Bvsp = (2Bv1 + Bv2) / 3 AF3 Bvsp = Bv2 AF4 Bvsp = (2Bv3 + Bv2) / 3 AF5 Bvsp = Bv3 AF3 Bvsp = (Bv1 + 2Bv2 + Bv3) / 4 AF2 + AF3 Bvsp = (Bv1 + Bv2) / 2 AF2 + AF3 + AF5 Bvsp = (Bv1 + Bv2 + Bv3) / 3 AF5 + AF3 Bvsp = (Bv2 + Bv3) / 2 AF2 + AF5 Bvsp = (Bv1 + Bv3) / 2 If the range is AF1, AF3, AF5, only the metering range that includes it
Use the photometric value of When the latest range is AF2 or AF4, the size of the subject is large.
Depending on the size, it is often within the metering range at the center.
(2Bv1 + Bv2) / 3 or (2Bv3 + Bv2) / 3 is set as the photometric value BOSP of the subject. If the latest range is AF3, the subject is considered large and
After increasing the weight of the middle photometry range using the light range, (Bv1 + 2B
v2 + Bv3) / 4 is set as the photometric value BOSP of the subject. AF area AF3 and AF1
Or AF2 or AF1 and AF2 are recent, or AF areas AF3 and AF4 or
Is the photometry of the center AF area AE2 when AF5 or AF4 and AF5 are recent.
The value Bv2 and the photometric value Bv1 of the photometric range AE1 or the photometric value Bv3 of the photometric range AE3
, Ie, (Bv1 + Bv2) / 2 or (Bv2 + Bv3) / 2
. Distance measurement areas AF3 and AF1 or AF2 or AF1 + AF2, and AF4 or AF5
Alternatively, when AF4 + AF5 is recent, the photometric value of the subject is (Bv1 + Bv2 +
Bv3) / 3 is used. AF1 or AF2 or AF1 + AF2 and AF
If AF4 or AF5 or AF4 + AF5 is recent, the photometric value Bvsp of the subject is used.
(Bv1 + Bv3) / 2. Returning to FIG. 19, the microcomputer μc calculates the average photometric value Bvav by (Bvsp + Bv4
) / 2, and calculates the exposure value Evsp and the average exposure value Evav of the subject respectively [Bvsp
+ Sv (Sv; film sensitivity)] (Bvav + Sv) (# 615, # 6
20). When the two exposure values Evsp and Evav are equal to or less than the predetermined value 9FEv,
Steps from steps # 625 and # 630 to start flash photography as underexposure
Go to # 635. In step # 635, a flag FLF indicating flash photography is set.
In order to make the background appropriate, the exposure value is set as a photometric value Bv4 in the photometric range AE4.
The exposure value of the photometric value Bv4 is set, and the process returns. At least one is a specified value
If not, the process proceeds from step # 625,635 to step # 630.
The average photometry value and the photometry value of the subject are used to detect whether the backlight is
Bvsp, and if the difference is 2 Ev or more, the backlight
Proceeding to step 635, control is performed to perform flash photography. When the above difference is less than 2
, And returns with the average exposure value Evav as the control exposure value Ev. Upon completion of the exposure calculation processing, the microcomputer μc presses the release button S2.
It is determined whether or not the photographing preparation switch S1 is turned on.
Is determined (# 125, 130). Switch S1 is ON
In this case, it is determined whether or not flash photography has been performed. If flash photography has been performed (FLF = 1), charging is controlled, and the process returns to step # 125.
If F = 0, the process returns to step # 125 without performing charge control (# 13).
0-140). When the release button is pressed in step # 125, a shooting operation is performed.
. The details are shown in FIG. 17 and explained. The microcomputer μc is based on the latest distance information.
And the lens is extended (# 705). When the extension is over, is it flash photography?
It is determined whether or not the flash photography is performed (FLF = 1).
= FXD (GN = guide number, F = aperture value, D = distance) (# 72
0). Then, based on the exposure value Ev obtained in step # 640 (FIG. 19),
When the shutter is opened and the aperture value reaches the specified value, flash light is emitted and the specified exposure
Close the shutter when it comes out, and after closing the shutter,
Control is performed (# 720-730). Step # 710
When flash photography is not performed (FLF = 0), step # 635 (FIG. 19)
After performing exposure control based on the exposure value of ()), the lens is retracted and the routine returns
. Regarding the sequence (lens drive, exposure control) in the photographing operation,
Since it is not a title, it is a simple explanation. Returning to FIG. 13, the photographing operation ends. It controls the winding of one frame. This is the second
Referring to FIG. 0, the microcomputer μc outputs a winding start signal, and the completion of winding is determined.
Wait for the indicated switch S3 to be turned on (# 805, 810). Switch S3 is O
N (I1 = “L”) stops the motor and turns off the motor after stopping.
Is returned (# 815, 820). After completing the control of winding one frame,
Μc waits until the photographing preparation switch S1 is turned off, that is, the photographing operation ends.
When the switch S1 is turned off (I3 = “H”), the power supply
The transistor is turned off (OT4 = “L”) and the process proceeds to step # 20 (# 155-1).
65). In step # 130, without photographing (switch S2 = OFF
If the photographing preparation switch S1 is turned off, the process proceeds to step # 160, and # 16
Control of 0 or less is performed. In the above embodiment, the multi-point distance measurement method sets the short distance measurement area at the center of the distance measurement operation.
The distance measurement is performed by sequence control for all the distance measurement areas of the short distance measurement area and the five-point distance measurement area.
Even if the distance measurement value is determined to be a short distance for each of the specified distance measurement areas, the distance measurement operation is performed again by setting the short-distance light receiving element group and performing the distance measurement again. Effect
Can be obtained. G. Advantageous Effects According to the present invention, different distances are obtained by using light receiving means for measuring the distance in different areas.
A wide range of distances can be measured without requiring special equipment
It is now possible to perform distance measurement at

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining the arrangement of a light emitting element LED and a light receiving element SPC, and FIG.
F is a circuit configuration diagram of FIG. 3, FIG. 3 is an explanatory diagram of a distance measurement area and a photometry range, FIG. 4 is a circuit configuration diagram of one embodiment of the present invention, FIG. 5 is a circuit configuration diagram of a photometry circuit BV, FIG. FIG. 7 is an explanatory diagram of the distance measurement of the present invention, FIG. 7 is a diagram showing the relationship between the distance measurement distance and the signal ratio of the present invention, and FIG.
FIG. 9 is a detailed circuit diagram of the selection circuit CH4, FIG. 10 is a detailed circuit diagram of the selection circuits CH5 to CH8, FIG. 11 is a detailed circuit diagram of the shift register SR1, and FIG. FIG. 13 is a flowchart of the operation of the interrupt INT0, and FIG.
FIG. 14 is a flowchart of a distance measuring operation, FIG. 15 is a flowchart of a photometric operation, FIG. 16 is a flowchart of a charging control, FIG. 17 is a flowchart of a photographing operation, and FIG. 18 is a film sensitivity reading operation. 19 is a flowchart of the exposure control, FIG. 20 is a flowchart of the one-frame winding operation, FIG. 21 is an explanatory diagram of the distance measurement of the conventional example, and FIG. 22 is a diagram of the distance measurement and the signal ratio of the conventional example. FIG. SPC3, SPC4 ... first light receiving means, SPC4, SPC5 ... second light receiving means, AF ... calculating means, LED3 ... first light emitting means, LED4 ... second light emitting means, # 75 ... first timing , # 85 ... second timing, # 105 ...
Third timing, SPC3: first light receiving element, SPC4: second light receiving element, SPC5: third light receiving element.

Claims (1)

[Claims] Claim 1. A distance measuring device that projects light to an object field and calculates a distance to the object by receiving reflected light from the object, and projects light in different directions of the object field at different timings. A distance measuring device capable of measuring a distance in a plurality of regions in a field of view by projecting the light into a first region at a predetermined timing and reflecting the light from an object within a first distance range in the first region A first light receiving means for receiving the reflected light; and a light receiving means for receiving light projected onto the first area at a timing different from the predetermined timing and reflected by a subject within a second distance range in the first area. And the second
A second light receiving means for receiving light projected on the area and reflected by a subject in the second area; and a first distance in the first area according to a result of the light reception by the first light receiving means. A first distance measurement result representing the subject distance within the range is obtained, and a second distance measurement result representing the subject distance in the second region is obtained in accordance with the light reception result by the second light receiving means; Calculating means for obtaining a third distance measurement result representing a subject distance within a second distance range within the area of (a). Claim 2. 2. The measurement system according to claim 1, further comprising: first light projecting means for projecting light to the first area; and second light projecting means for projecting light to the second area. Distance device. Claim 3. The first light receiving means receives the light projected to the first area by the first light emitting means at the first timing, and the second light receiving means is a second light emitting means. 2. The method according to claim 1, wherein the light projected to the second area is received at a second timing, and the first light projecting means receives the light projected to the first area at a third timing. 2. The distance measuring device according to 2. Claim 4. The first light receiving means comprises a first light receiving element and a second light receiving element, and the second light receiving means comprises the second light receiving element and a third light receiving element. Item 3. The distance measuring device according to Item 3. "