JPH01288834A - Range finding and photometric unit - Google Patents

Abstract

PURPOSE:To easily secure high relative accuracy of a range finding position and a photometric position, and to obtain a correct focus and exposure by placing a photodetector for range finding for an object to be photographed and a photodetector for measuring a luminance of the object to be photographed, on the same mask pattern on the same printed circuit board. CONSTITUTION:On a body of a range finding and photometric unit, a light emitting port of an LED, a photodetecting port for range finding and a photodetecting port for a photometry are provided in prescribed positions. On a printed circuit board 11 of the unit, photodetectors (SPC) 13, 14 for range finding and for a photometry are provided in prescribed position of a pattern 12 on the board 11 in a position relation opposed to each photodetecting port for range finding and for a photometery on the body. In such a way, when two kinds of AF use SPC 13 and AE use SPC 14 are loaded on the conductor pattern on the same board 11, as for a relative position of these two SPCs, it is considered that the relative accuracy of the pattern is extremely high, therefore, an error only is left against the pattern, and the relative accuracy is improved remarkably. In such a way, a correct focus and exposure can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a distance measurement/light measurement unit for measuring the distance and brightness of a subject within a photographic screen.

[Prior Art] Traditionally, distance measurement and photometry devices for cameras have been used to focus on the closest subject within the photographic screen, and at the same time to adjust the exposure to match the brightness of the subject within the range within the screen. What I tried to give is known.

By the way, some of these distance measurement and photometry devices are equipped with automatic focus (AP) and automatic exposure (AE) functions when taking pictures, and are designed to lock AP and AE at the same time due to their functionality. In such a device, in particular, relative accuracy with respect to the position of the object being measured by the AP is required. This tendency is more pronounced when the photometry range is wide.
Although this is not a problem, in order to more accurately detect the main subject and obtain proper focus and exposure, it becomes necessary to measure distance and light at multiple points within the shooting screen, so the light metering range is narrow. Therefore, the above relative accuracy is strictly required. In other words, if the relative precision between the distance measurement position and the photometry position deviates, the subject position to be measured and focused will be different from the subject position to be main photometered.

However, in conventional distance measurement and photometry units, the AE
The light-receiving lenses and light-receiving elements for AE and AE are placed on different printed circuit boards, and no special consideration has been taken to improve the accuracy of their relative positions. It took some time to secure it.

By the way, if we consider the case where each light receiving element is mounted on a separate board, the main error factors related to the relative relationship between the two light receiving elements are: - Misalignment between the reference hole of the board and the conductor pattern, - The conductor Examples include pattern misalignment, and (1) tolerance between the reference hole on the board and the positioning boss on the board.

As a result, it has not been easy to ensure high relative accuracy in the positions of the two light receiving elements.

[Problem U to be solved by the invention] The present invention has been made to address the above-mentioned requirements, and in order to obtain proper focus and exposure, the photometry range is narrowed, especially when performing multi-point distance measurement. It is an object of the present invention to provide a distance measurement/photometering unit that can easily ensure high relative accuracy between a distance measurement position and a photometry position, which is required due to the above.

[Means for Solving the Problems] The present invention provides a distance measurement and photometry unit that includes a light emitting and light receiving element for measuring the distance to a subject and a light receiving element for measuring the brightness of the subject. and a light-receiving element for measuring subject brightness are arranged on the same mask pattern on the same printed circuit board.

[Function] According to this configuration, it is only necessary to recognize the positions of two light receiving elements on the pattern and mount them, and the positional accuracy of the mask pattern on one substrate can be said to be extremely high. The position is only a placement error with respect to the pattern.

[Example] Fig. 1 shows a distance measurement/photometering unit according to an embodiment of the present invention viewed from the subject side, and Fig. 2 shows the rear case of the unit and the printed circuit board on which the light receiving element is mounted. Indicates the condition removed. In addition, Figures 3 (a) and (b) and Figure 4 show the printed circuit board, which is the main part of the unit, and Figure 5 (a).
) to (e) are the light emitting and receiving lenses, Fig. 6<a) to (
C) each shows a photometric lens.

First, in Figures 1 and 2, 1 is a distance measurement/photometering unit, 2 is a lens of the camera to which the unit 1 is attached, and 3
4 is the light projection lens that emits LED light toward the subject for distance measurement, 4 is the same lens frame, 5 is the light receiving lens that receives the reflected light from the subject, 6 is the same lens frame, and 7 is the brightness of the subject. 8 is a photometric lens frame for photometry.

In addition, the body of the unit 1 includes an LED light emitting port 4a.
, a light receiving port 6a for receiving reflected light for distance measurement, and a light receiving port 8a for photometry, and bosses 9 and 10 for positioning and fixing a printed circuit board (to be described later) at a predetermined position on the body.

Next, in FIG. 3 (a>(b)) and FIG. 4, 11 is a printed circuit board, 12 is a part of the mask pattern on the same substrate 11, and 13 and 14 are silicon photo cells, etc., respectively. It is a light receiving element (hereinafter referred to as SPC) for distance measurement (AP) and photometry (AE), and these 5 for AP
The PC 13 and the AEE5PC 14 are positioned to face the light receiving ports 6a and 8a of the body, respectively. 15
16 is transparent resin, 17.18 is for AP and AE
This is a filter for Furthermore, holes 9a+10a are formed in the substrate 11 in correspondence with the bosses 9.10.

To explain these mounting procedures, each 5PCI 3.14 is placed at a predetermined position of the pattern 12 on the board 11, and each terminal and the pattern are electrically connected with wire.
A frame 15 is arranged to cover the frames 13 and 14, and a transparent resin 16 is injected into the frame 15, and the AF filter 1 and the AE rough filter 18 are sealed from the outside air. and,
The board 11 has its holes 9a and 10a and the bosses 9 and 10 of the body.
It is then positioned and mounted. In addition, A in Fig. 4,
Part B is AFyASPCl3, AEE5PC, respectively.
14 are implemented, and in detail, these SPCs
are placed on the conductor patterns 12a and 12b.The SPC die bonder can be mounted while recognizing the position of the conductor patterns, and its installation can be performed with high precision of approximately ±50μ relative to the pattern outline. can be kept. Thus, when two types of 5PCs 13 and 14 are mounted on the conductor pattern on the same board, these two SPCs
Since the relative position of the pattern is considered to have extremely high relative accuracy, the only error is the placement error with respect to the pattern, and the relative accuracy is greatly improved compared to the conventional mounting configuration.

Next, the basic principle of distance measurement in the present invention, particularly the active triangulation method, will be explained using FIGS. 7 to 9, 10 to 12, and 13 to 14. .

First, conventionally known systems are shown in FIGS. 7 to 9. The light projected from the LED through the projection lens 3 is
Depending on the subject distance 131 to S5, 5PC(Di), (
D2) Move above.

If these outputs are 5PCI and 5PC2, and the ratio of 5PC2/5PCI is taken according to distance measurement, the result will be as shown in FIG. 9. Since this ratio is constant regardless of the reflectance of the subject, the distance to the subject can be measured by measuring the ratio. By the way, in this method, when the subject distance is close to 84, S5, 5P
The problem is that the slope of the C2/5PCI ratio becomes gentle, making it difficult to judge the distance.

Therefore, in Fig. 10 to Fig. 12, a configuration is adopted in which the light of the LED moves on 5 PCs (Di) (D2) (D3) according to the subject distance, and the LED is emitted twice, and - takes the ratio as 5PC2/5PCI, and the second time is 5PC3/
I try to take the ratio with 5PC2. As a result, 34
．． The slope of the ratio can be kept constant up to a distance as short as 35, making distance measurement possible.

FIGS. 13 and 14 show an embodiment of the present invention that further develops this idea. Here, multiple LEDs (Ll
~L5) and (Di~D6), a plurality of SPCs from which outputs are taken out for each LED are appropriately selected.

That is, 5 PCI for LED (LL) I, 2, 3 .
Then, distance measurement is performed according to the procedure shown in Figures 10 to 12 above, and further LED (5PC2, 3, 4
Therefore, 5PC3,4゜5 for LED (L3), 5PC4,5゜6 for LED (L4),
Distance measurement is performed for the LED (L5) by 5PCs 5 and 6, respectively. In this way, it becomes possible to accurately measure the distance to a wider range of objects.

Hereinafter, a camera equipped with the distance measuring/photometering unit of the present invention will be explained using FIGS. 15 to 30.

FIG. 15 shows a circuit block in a camera in which this distance measurement/photometering unit is used. The shutter of the camera uses an aperture shutter. μC is a microcomputer (hereinafter referred to as microcomputer) that performs the entire camera sequence and various calculations.
, power is supplied via a reverse charge prevention diode D1.

C is a backup capacitor, AP is an active type distance measuring circuit that measures the distance to the subject, DX is a film sensitivity reading circuit that reads the film sensitivity of the film given the film sensitivity code, and Bv measures the brightness of the subject. This is a photometering circuit. The distance measurement data from the distance measurement circuit AP, the film sensitivity data of the film sensitivity reading circuit DX, and the photometry data of the photometry circuit F6Bv are sent from the selection circuits CH1 to CH8 via the shift register SR.
It is sent to the microcontroller μC. Al! A description of the I-range circuit AF and photometry circuit Bv, and data transfer to the microcomputer μC will be described later.

AE is an exposure control circuit, which receives a pulse φ1 from the microcomputer μC.
, φ2, the shutter is opened and closed according to the phase and number of φ2. LE is a lens drive circuit, and based on the distance measurement data,
0MO that extends and retracts the lens depending on the phase and number of pulses φ3 and φ4 from the microcomputer μC.
is a one-frame winding circuit, and the signals Ml and M2 from the microcontroller μC
ST is an electronic flash device that controls the charging control signal CHC from the microcomputer μC to start and stop boosting, and emits light according to the light emission start signal X. ) outputs a signal CHD indicating the charging state of the battery. Tri is distance measurement circuit AF, film sensitivity reading circuit DX, photometry circuit Bv
This is a power supply transistor for supplying power to the The microcomputer μC and circuits other than those described above are directly supplied with power from the power supply E. Xr is a crystal oscillator, and the microcomputer μC operates using two types of clocks obtained by dividing the tarok sent from this crystal oscillator.
This is to issue a warning when the capacitor of the flash device does not reach a predetermined voltage when necessary for flash emission.

Next, to explain the switches, SO is a main switch (not shown), and the one-shot circuit 031 outputs pulses in response to the rise and fall of the signal due to ON and OFF of this switch.The one-shot circuit 031 outputs pulses to the microcontroller μC. The microcomputer μC inputs this and executes the interrupt INTO. SL is a shooting preparation switch that is turned on by pressing the first stage of the release button. When this switch is turned on, a pulse is output from the one-shot circuit O32, and the microcontroller μC
executes the interrupt INTO, which will be described later. S2 is turned on when the release button is pressed in the second step (deeper than the first step), and the microcomputer μC responds to this and performs a shooting operation.S3 is turned on when a predetermined length of film is wound up. It is a one-frame switch and turns OFF when a release operation is performed.

Next, details of the distance measurement circuit AF and the photometry circuit By, and the distance measurement range and photometry range occupying the photographic screen will be explained. FIG. 16 shows the distance measurement range and photometry range occupying the photographic screen. The outermost frame FLM is the shooting screen, and the five AFL to A indicated by solid lines
F5 is the distance measurement range, and the four dotted lines AEI to AE4 are the photometry ranges.In this way, multi-point distance measurement and multi-point light measurement are performed, but as a general rule, the selection of the distance measurement value depends on the camera. The closest subject is taken as the main subject, the photometry value of the photometry range AEI to AE3 that includes the distance measurement range is taken as the photometry value of the main subject, and the photometry value of the main subject is compared with the photometry range AF4 to detect the backlight condition. are doing.

Details of how to measure distance and determine photometric values will be described later.

Among photometry ranges ABI to AE3, photometry ranges: AEI, AE
3 are distance measuring ranges (AFL, AP2), respectively.

(AF4, AF5), and the photometry range AE2 includes only the distance measurement range AF3.

The reason why the photometric range AE2 is configured and arranged in a vertically elongated manner compared to the photometric ranges AEI and AE2 is to: 1) make the area the same as the photometric range of the pond, thereby eliminating the need to adjust the photometric output due to the difference in area; and (1) The main subject is often located in the center, and in this case, the main subject is often vertically long (particularly a human).

AF6 shown in the distance measurement range AFB in the figure indicates that the distance measurement range is expanded only in the center distance measurement range, and the distance measurement ranges AF1 to AF5 are 1 m% - (X), the distance measurement range A
F6 measures a distance of 0.5m to 1m. The reason for widening the distance range for measuring only the central part is that as the distance gets closer (0.5m to 1m>), the main subject becomes larger, and by measuring only the central part, it is almost impossible to miss the main subject. It depends.

The distance measurement and photometry unit of the present invention is based on active type triangulation, so the light emitted from the light emitting element and reflected from the subject is received by two light receiving elements, and the ratio of the two light receiving elements is calculated. The distance is detected by this.

In this embodiment, as shown in FIG. 17, five light emitting elements LED (LEI to LE5) and light receiving elements 5PCI to 5PC are used.
It consists of 6. Table 1 shows the relationship between the combinations of these light emitting elements and light receiving elements and the range of distance measurement.

(v dimension 4' Table 1 (H indicates hexadecimal) In the distance measuring range AF6, LED3 is used as the light emitting element, but unlike in the case of the distance measuring range AF3, the light receiving element is separated by a base line length. By using 5PC4 and 5PC5, it is possible to measure a closer distance.If you want to measure an even shorter distance, you can use the light receiving elements 5PC5 and 5PC6.

FIG. 18 shows a specific configuration of the ranging circuit AP.

In the same figure, MPXI is a multiplexer and microcontroller μ
As shown in Table 1, the signal 0TI from C (corresponding to the distance measurement range AF1 to AF6) changes the distance measurement range and the outputs 1 to 1 to cause the LED to emit light according to the signal from the microcontroller μC. Output rH and level to any one of 5. MPX2 and MPX3 are the signals OT from the microcontroller μC.
This is a multiplexer that outputs one of the input signals so that the relationship between the distance measurement range and the light receiving element SPC shown in Table 1 is established by I. C2 is a capacitor for supplying energy to the light emitting elements LEDI~5, AN1~AN5. T
r2 to Tr6 are light emitting elements LEI to LE according to the ranging range.
5 is an AND circuit and a transistor for emitting light in response to the ranging start signal AFS.

ANC1 to ANC6 are analog circuits for extracting the light from the light emitting elements reflected from the subject and outputting it as a logarithmically compressed signal. DI FAMP is a differential circuit that takes the difference between the outputs from the multiplexers MPX2 and MPX3. Note that since the difference between the logarithmically compressed signals is taken, the ratio of the input signals of the light receiving element is actually taken. 01~C
8 is a comparator for detecting the level of the differential circuit, and the latch circuit connected to this latches the output of the comparator by the signal of the circuit delay that delays the AP start signal, and outputs it to the selection circuits CHI to CH8. do. The reference voltage of the comparators C1 to C8 is formed by a constant current circuit and a ladder resistor.

FIG. 19 shows a specific configuration of the photometric circuit Bv.

In the figure, light receiving elements 5PCII to 5PC14 correspond to the photometric ranges AEI to AE4 shown in FIG. 16, and Table 2 shows this relationship and the relationship of signals input to multiplexer MPX4, which will be described later.

The photometric circuits ANCII to ANC14 in Table 2 include the light receiving element 5PC1.
It processes the output currents from 1 to 14 and outputs a current according to the brightness. The photometric circuit ANC14 corresponds to the photometric range AE4, and since its area is larger than the photometric ranges AEI to AE3, the current difference for the same brightness is different. Photometric circuit ANC
14, the current for the same brightness is shown in the photometry range AEI~
It is corrected within the circuit so that it is equal to the circuit ANCII-13 of AE3. The multiplexer MPX4 uses the signal OT2 from the microcomputer μC to connect the photometry circuit ANC1.
Outputs 1 to 14 are selected and one of them is input to a double integral A/D circuit (DCA/D) shown below.

Double integral A/D circuits (DCA/D) are well known.

To briefly explain its general configuration, CHG is a charging/discharging circuit that charges a capacitor (not shown) during the "H" period of the signal ADS indicating the start of A/D conversion from the microcontroller μC. When the voltage is set to a predetermined value and the A/D start signal ADS becomes “L” level, the photometry circuit AN
This is a circuit that controls discharging with a current according to the brightness of CII~14, and when the voltage of the capacitor drops to a predetermined voltage due to discharge, the "L" level A/
Outputs D end signal ADH. The AND circuit AN11 and the counter CNT are for counting the time during which the above-mentioned discharge is being performed, and when the A/D start signal ADS is "L"
”, the counter CNT counts the clock sent from the microcomputer μC until the charging/discharging circuit CHG outputs an “L” level A/D end signal. It is short (fewer clocks to count), and Kanuta is 4.
It is composed of bits, and each output is selected by a selection circuit C.
Output to HI~CH4.

Next, the specific configuration of the selection circuits CHI to CH8 will be explained in the second section.
FIG. 20(a) shown in FIGS. 0(a), 20(b), and 20(c) corresponds to the selection circuits CHI to CH3, and each receives a ranging signal, a photometric signal, and a DX signal (film exchange) as information signals. Distance measurement circuit AP, photometry circuit AE, and DX circuit DX
Distance measurement control signal AFC5 and photometry control signal ABC and DX control signal D control these signals respectively.
The configuration is such that the XC is input from the microcomputer μC and a signal corresponding to the control signal is passed through. FIG. 20(b) shows the selection circuit CH4, and FIG. 20(C) shows the selection circuits CH5 to CH8.
Corresponding to this, the three signals in FIG. 20 are reduced to two (distance measurement/photometry) and one (distance measurement), respectively.

Figure 21 shows one of shift registers SR1 to SR8.
To explain the latching and transfer of the signal from the 0 selection circuit CHI, which shows the configuration of RI, first, when the latch signal LCH of the rH level is sent from the microcomputer μC, the one-shot circuit O3H operates, and the Generates a pulse. Then, during the "H" level period of this pulse, the AND circuit AN28 becomes active, and the signal of the selection circuit CHI is input to the D input of the latch circuit DFF22. During the "H" level period of the one-shot circuit 0811, a clock is input from the microcomputer μC, and in synchronization with the rise of this tally, the latch circuit DFF22 selects the selection circuit CH.
The signal from I is latched and output from output terminal Q. The pulse from the one-shot circuit 0311 is designed to disappear (fall) before the first pulse from the microcomputer μC falls. The microcomputer μC takes in the data output from the shift register SRI in synchronization with the falling edge of the clock.

The shift register SR1 sequentially connects the latch circuit DFF of the previous stage shift register SR2 according to the second and subsequent tarlocks.
21 output signal is latched and outputted. Microcomputer μC is 8
In synchronization with this clock, the shift registers SRI to SR8 sequentially output the data of the selection circuits CH1 to CH8 to the microcomputer μC. Serial transfer SI
Call it O.

The operation of the camera having the above configuration will be explained based on the flowchart of the microcomputer μC shown in FIG. 22 and subsequent figures. When the main switch SO (not shown) is operated (step #5
YES), a pulse is output from the one-shot circuit O3I to the interrupt terminal INTO of the microcomputer μC, and
inputs this and executes the INTO interrupt shown in FIG.

The microcomputer μC is OF whether the switch SO is turned on or not.
Detect whether it is set to F by the level of the input terminal IO, and if it is turned on (IO = rL,), it is assumed that photography will be performed, and the output terminal and flag should be initially set #1
0), enable the interruption lNTl by the photographing preparation switch S1 #15), and perform charging control of the electronic flash device (#20).
).

A subroutine for this charging control is shown in FIG.

In this routine, whether the electronic flash device ST is fully charged is detected by the signal CHD, and if the charging is not completed (CHD=rLJ), the boost control signal CHC is detected.
to r HJ level and start boosting (#205
, 210). Next, it is necessary to detect whether the switch S1 is turned on or not based on the level of the terminal wire 3 (#215).
If it is (Step 3 = "L"), set the terminal OT3 to "H" level to display the LED (red) to indicate the uncharged state (#220), and return to the previous step #205.

Regarding the display of this LED, please refer to step #140 described below.
It becomes effective when the interrupt INTO occurs, and when the shooting preparation switch S1 is OFF (I3=
``HJ)'', connect the terminal (OT3) to turn off the LED.
Step #215, 217), Step #20
Proceed to step 5.

On the other hand, charging is completed in step #205.
Alternatively, when charging is completed (CHD = "H"), the boost control signal CHC is set to "L" level to stop boosting (#225), and when the shooting preparation switch S1 is turned on (IT3 = 'rLJ). ), turn off the LED 0T3=
"L"), return (#230, 235). At step #230, the shooting preparation switch S1 is turned OFF (
When IT3=TH3), it returns immediately.

Returning to Fig. 22, when the charging control is finished, the microcomputer μC
turns off the power supply transistor T r 1 (OT4=r
charging is stopped (#25).

Stopping here means stopping the clock as well, so that the taro clock can be restarted by an interrupt.

In step #5, when the main switch SO is turned off, an interrupt lNTl is generated by the photographing preparation switch Sl.
(#30), proceed to step #25, and turn off the power supply transistor T r1 (OT4= rL")
Stop as.

Next 6; Interruption by the shooting preparation switch S1 NTl
To explain this with reference to FIG. 23, when the photographing preparation switch S1 is turned on, the one-shot circuit O is activated in response to this signal.
A pulse is output from 82, and the microcomputer μC receives this pulse and executes the interrupt lNT1 process. First, the microcomputer μC stops boosting the electronic flash device (C, HC= rL
J) (#35), stabilize the power supply voltage, turn on the power supply transistor Tri (OT4 = rH"), and supply power to each circuit (#40), and the distance measurement and photometry circuits are in a stable state. The microcomputer μC then switches the tarok from low speed to high speed for execution processing (#50) to shorten the time required for data processing, especially data transfer. . Note that until switching to a high-speed clock, the microcontroller μC is running on a low-speed clock.Distance measurement data for 5 distance measurement ranges and photometry for 4 photometry ranges are obtained by repeating A/D conversion for distance measurement and photometry. Obtain data (#55 to #95).

Flowcharts of A/D conversion for distance measurement and photometry are shown in FIGS. 24 and 25, respectively. First, the operation for distance measurement (detection) of the distance measurement range AFL shown in FIG. 24 will be explained. Outputs a signal indicating 0H (H indicates a hexadecimal number) from OT1 and specifies that distance measurement range AF1 be measured (
#305) Then, the ranging start signal AFS is set to rH level, and the infrared LED 1 emits light using the energy of the capacitor C2 via the AND circuit AN5 in FIG. Furthermore, the infrared light reflected by the subject is input to the light receiving elements 5PCI and 5PC2, and the multiplexer MP
Comparators C1 to C8 compare the data via X2 and differential amplifier DI FAMP, and the distance measurement data is latched by a latch circuit. The microcontroller μC waits for this time (#31
5) As mentioned above, set the ranging control signal to the "rH" level, make the selection circuits CHI to CH8 select the ranging signal, set the latch signal to the "H" level, and start the serial data transfer SI.
By performing O, the distance measurement signal is latched and the data is sent to the microcomputer μC, which takes in this signal (#320 to 330).

Then, all the signals, including the distance measurement start signal AFS, the distance measurement control signal AFC, and the latch signal set to the "H" level, are returned as "L" level (#335 to 345), ft!
! The distance measurement operation in the distance measurement range is also the same, except that the signal output from the terminal OTI differs depending on the distance measurement range, as shown in Table 1.

Next, A/D conversion of the output from the photometric circuit and this A/D conversion are performed.
Control of importing D-converted data will be explained with reference to the flowchart of FIG. 25. Microcomputer μC has terminal O
A signal indicating the photometry range is output from T2. Since the photometry range is now AEI, a signal OH indicating this area is output (#405). In the photometric circuit Bv of FIG. 19, the multiplexer MPX4 connects the output of the light receiving element 5PC11 to the double integration A/D conversion circuit DCA/D.

The microcomputer μC then outputs an "H" level A/D conversion start signal ADS (#410), and in response to this, the charging/discharging circuit CHG starts charging the capacitor in the above-mentioned manner, After waiting the time required for this charging, the microcomputer μC sets the A/D conversion start signal ADS to the "L" level (#415 to 420), and the charge/discharge circuit CHG changes the photometry output from the charged capacitor. The discharge will start accordingly. The microcomputer μC starts outputting the clock CLK2, waits for the input of the signal ADH indicating the end of A/D conversion from the double integration circuit <DCA/D), and when this is input, stops outputting the clock CLK2 ( #425
~435). Next, set the photometry control signal BvC to r) (J level, set the latch signal to "H" level, perform serial transfer control SIO, and input photometry data (8440~
450). Then, the signal LCH set to the above rH level
, BvC is set to "L" level and returns.

Control regarding A/D conversion and input of the data to the microcomputer μC in the photometric range of the light source is the same, except that the data of the signal output from the terminal OT2 differs depending on the photometric range.

Here, the reason why distance measurement and photometry are performed alternately is as follows.
As mentioned above, in the distance measuring circuit (Fig. 18), the LED
The energy of is supplied from capacitor C2, - degree LED
This is because it takes time to charge the capacitor after it emits light, and if distance measurement is performed continuously before the capacitor is fully charged, sufficient light will not be emitted and the range that can be measured will be reduced. It will be limited to the far side. In order to take this charging time, after distance measurement, A/D conversion for photometry and data input to the microcomputer are performed. This photometric A/D conversion,
The time required to input data to the microcomputer is approximately 10 nsec, which is sufficient time to charge the capacitor C2. It is conceivable to perform distance measurement five times in succession, but at this time it is necessary to obtain time to charge capacitor C2 (
Here, the total release time lag is longer (40 n5ec here), which causes problems such as image blurring and a reduction in the number of consecutive frames per second when photographing a moving subject. Returning to Figure 23 and continuing the explanation, microcontroller μC
After completing the distance measurement in the distance measurement range AFS, the capacitor C2
Wait for time to charge the battery, change the distance measurement range of distance measurement range AF3 to the near side, and perform distance measurement of distance measurement range AF6.Here, only the center distance measurement range of the near side is performed. Although it is possible to use the entire distance measurement range, in such a case,
it takes time. Considering that we are measuring a subject (human) at a short distance (assuming a distance of 0.5 to 1.5 m), the subject will be relatively large and will include most of the ranging range shown in Figure 16. Therefore, it is sufficient to measure only the central part.

In addition, in this distance measurement, as mentioned above, by using LED3 as the LED and 5PC4 and 5PC5 as the light receiving elements, the baseline length is lengthened to make it suitable for the near side distance. The determination of the distance in the near distance measuring range AF6 is performed by processing within the microcomputer μC to which the signal from the distance measuring circuit is input.

Next, the sequence for inputting film sensitivity will be explained with reference to the flowchart of FIG. The microcomputer μC sets the film sensitivity control signal DXC to rH.

level, the selection circuit CH outputs a signal indicating the film sensitivity, and the latch signal LCH is set to rH.

level and input film sensitivity data by serial transfer SIO (#505 to 515),
Then, latch signal LCH, film sensitivity control signal DX
Set C to “L” level and return (#520.#5
25).

After controlling the data transfer as described above, the microcontroller μ
C uses a low-speed processing clock to reduce current consumption (#110 in FIG. 23).

Then, the latest distance range is detected from the distance measurement data of the entire distance measurement range (#115).

Next, exposure calculation is performed to determine the exposure value, and the details will be explained with reference to the flowchart of FIG. 29. First, the photometric value Bvs of the subject is determined based on the range closest to the camera.
Determine p as shown in Table 3*ts,
(V×, mind) Son 3 table recent range is API, AF3. If it is AF5,
Use the photometric values only for the photometric range that includes it. The recent range is AF2. When using AF4, depending on the size of the subject, it often falls within the metering range at the center, so
Including the central part, each (2B v l +B v 2
) / 3 or (2Bv3+ B V 2 ) /
3 is the photometric value Bvsp of the subject.

If the recent range is AF6, consider that the subject is large, use the entire metering range, increase the weighting of the middle metering range, and then calculate (Bvl + 2Bv 2 + Bv
3) /4 is the photometric value Bvsp of the subject.

As shown in Table 3, if distance measurement range AF3 and API or AP2 or (AF2+AF3) are recent, or if distance measurement range AF3 and AF4 or AF5 or (
AF4+AF5) are recent, the average of the photometric value BO2 of the central photometric range AE2 and the photometric value Bvl of the photometric range AEI or the photometric value Bv3 of the photometric range AE3, respectively;
That is, (B v 1 +B v 2 )/2 or (BV2+BV3)/2. Also, distance measurement range AF3 and API or AF2 or (API operator AP2)
) and AF4 or AF5 or (AF4-1-AF5
) is recent, the photometric value of the subject is (Bvl+B
v2±Bv3)/3 is used. The distance measurement range is A
PI or AP2 or (AF1 AP2) and (AF4
) or if AF5 or (AF4+AF5) is recent, the photometric value Bvsp of the subject is (B v l +
Bv3)/2.

Returning to Figure 29, the microcomputer μC has the average photometric value Bvav
is calculated as (Bvsp+Bv4)/2, and the subject's exposure value Evsp and the average exposure value Evav are calculated as (Bvsρ+5v (Sv: film sensitivity)) (
Svav+Sv) (#615. #620),
The above rain exposure values EVsp and Evav are predetermined values (9Ev)
If it is below, it will be considered underexposed and you will need to take flash photography.
Step #625. The process advances from #635 to step #640.

In step #640, a flag FLF indicating flash photography is set, and the exposure is set to 1iiEv to make the background appropriate.
Let the exposure value be the photometric value Bv4+Sv of the photometric range AE4#
645), return. If at least one of them is greater than or equal to the predetermined value, step #625. From #635, the process advances to step #630, and in this step, in order to detect whether or not there is a backlight condition, the difference between the average photometric value and the photometric value Bvsp of the subject is calculated, and if the difference is 2Ev or more, As a backlight condition, the process proceeds to step #640, and control is performed to perform flash photography. If the above difference is less than 2Ev, the average exposure value Evav is set as the control exposure value E■ (#
650), return.

The explanation will be given again by returning to FIG. 23. After completing the above exposure calculation process (#120), the microcomputer μC releases the release fD.
It is determined whether or not s2 is pressed, and if it is not pressed, it is determined whether or not the photographing preparation switch S1 is turned on (#125, #130). If switch S1 is ON, it is determined whether or not flash photography is being performed, and if it is flash photography (FLF=1) (YES in #135).
To do this, perform charging control <#140) and proceed to step #12.
If it is not flash photography (FLF=0), the process returns to step #125 without performing charging control. When the release button S2 is pressed in step #125, a photographing operation is performed.

The details of this photographing operation will be explained with reference to FIG. 27.

The microcomputer μC advances the lens based on the recent distance information (#705). When the lens is extended, it determines whether or not it is flash photography (#710). If it is flash photography (
FCF=1), aperture value FM during flash photography is GN=FxD
It is determined from (GN=N guide number=aperture value, D=distance) (#720). Then, the shutter is opened based on the exposure value Ev determined in step #645 (Fig. 29), and a flash is emitted when a predetermined aperture value is reached, and the shutter is closed when a predetermined exposure is achieved. After closing, the lens aperture is controlled and the process returns (#720 to 730).

In step #710, when flash photography is not performed (FL
When F=O), exposure control is performed based on the exposure value in step 650 (FIG. 29), the lens is stopped down, and the process returns (#720 and #730). Regarding the sequence of shooting operations (lens drive, exposure control),
Since this is not the subject of the invention, this is a brief explanation.

Returning to FIG. 23, when the photographing operation is completed, the control on the spring is performed, which will be explained with reference to FIG. 30.

The microcomputer μC outputs the first ball start signal, drives the hoisting motor, and waits for the switch S3, which indicates the completion of piece hoisting, to be turned on (#805, #810). When switch S3 is turned on (11=rL"), the motor is stopped and the motor is turned off after stopping, and the process returns (#815.#82
0).

After completing the control for winding one frame, the microcomputer μC waits for the shooting preparation switch S1 to be turned off, that is, waits for the shooting operation to be completed, and then the switch S1 is turned off (13=rH). ) and turn off the power supply transistor.
(OT4= r'L") L, proceed to step #20 (Fig. 22) (#155 to 165), and step #13
0, switch S2 is OFF without photographing,
When the shooting preparation switch S1 is turned off, step #1
The process proceeds to step 60, and the control from #160 onwards is performed.

According to the above embodiment, proper focus and exposure can be given to the main subject by performing multi-point distance measurement, focusing on the closest subject, and at the same time giving exposure according to the brightness at that position. be able to. Here, in the present invention, the relative accuracy between the distance measuring position and the photometering position can be increased, so the above effects can be further enhanced.

[Effects of the Invention] As described above, according to the present invention, since the light-receiving element for measuring the subject brightness and the light-receiving element for measuring the subject brightness are arranged on the same mask pattern on the same printed circuit board, distance measurement is possible.・
Even without any complicated adjustment of the photometry position, the relative precision of these can be made extremely high, and as a result, accurate distance measurement and photometry for the main subject are possible.

[Brief explanation of the drawing]

Figure 1 is a front view of a distance measurement/light metering unit according to an embodiment of the present invention as seen from the subject side, Figure 2 is a rear view of the same unit with the rear case removed, and Figure 3 (a). , (b
) is a front view of the printed circuit board installed in the unit,
Figure 4 is a detailed view of the same printed circuit board, and Figures 5 (a) to (e).
) are diagrams showing the front, side cross section, side, rear, and cross sections of the light emitting and receiving lenses, respectively; Fig. 6 (a) to (c)
7, 8 (a> to (e)), and 9 are explanatory diagrams showing the basic concept of distance measurement method, and 10 Figures 11 (a) to (e) and Figures 12 (a) and (b) are explanatory diagrams of improved distance measurement methods, Figures 13 and 14 (a) to (e), respectively. ) is an explanatory diagram showing the principle configuration of distance measurement and photometry in the present invention, Fig. 15 is a circuit block diagram of a camera equipped with the present invention, and Fig. 16 shows distance measurement and photometry positions on the shooting screen of the same camera. FIG. 17 is an explanatory diagram showing its operation, FIG. 18 is a configuration diagram of the distance measuring device, FIG. 19 is a configuration diagram of the distance measuring device section, and FIG. 20 <a) to (c)
is a block diagram of the selection circuit, Figure 21 is a block diagram of the shift register, Figure 22 is a flowchart of the interrupt (INTO> routine), Figure 23 is a flowchart of the interrupt (INTI) routine, and Figure 24 is a flowchart of the interrupt (INTI) routine. Flowchart of the routine, Fig. 25 is a flowchart of the photometry routine, Fig. 2
Figure 6 is a flowchart of the charging routine, Figure 27 is a flowchart of the photographing operation routine, Figure 28 is a flowchart of the film sensitivity input routine, Figure 29 is a flowchart of the exposure calculation routine, and Figure 30 is a flowchart of the 1-frame winding routine. be. 1... Distance measurement/J+ light unit, 9.10... Boss,
9a, 10a... Hole, 11... Printed circuit board, 12
...Mask pattern, 13...Light-receiving element for distance measurement, 1
4... Light receiving element for photometry. Applicant Minolta Camera Co., Ltd. Agent
Patent Attorney Yasuo Itaya Figure 5 (a) (d) (b) (c) Figure 6 (a) (b) (C) No. 71'7I
Figure 9 Figure 10 Figure 11 Figure 12 (a) ':)1'; l bJ 'A b+1
3 Country Figure 14 Round 20r:A Figure 21 R2 Figure 24 Figure 25

Claims (1)

[Claims] (1) In a distance measurement/photometering unit equipped with a light-emitting and light-receiving element for measuring the distance to a subject and a light-receiving element for measuring the brightness of the subject, the light-receiving element for measuring the distance to the subject and the light-receiving element for measuring the brightness of the subject A distance measurement/light measurement unit characterized by being arranged on the same mask pattern on the same printed circuit board.