JPH05341179A - Distance measuring device and camera - Google Patents

Abstract

PURPOSE:To reduce wasteful outputs of light projection during close-up distance measurement so as to save power consumption by determining whether a selected range of distance measurement is a normal one or for close-up. CONSTITUTION:A microcomputer 10 detects the condition of a switch 11 to determine whether a selected range is a normal one or for close-up. The output of projection of light of an iRED 1 serving as a light projection means is varied according to the detection; i.e., during close-up distance measurement the output of light projection is lowered as compared with when the normal range is selected. The current iRED of the iRED is set to a smaller one so that power for the light projection of the iRED 1 is reduced. Since the power for light projection is thus set to a lower value from the beginning, the maximum power for light projection is decreased even with the range finding spot being out of the subject, so that power consumption can be saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device having a light projecting means for projecting light toward a distance measuring object and a light receiving means for receiving reflected light of the projected light on the distance measuring object. And an improvement of a camera provided with such an active or passive range finder.

[0002]

2. Description of the Related Art In recent years, a camera has been commercialized that is capable of shooting not only in a normal shooting range but also in a close range. Therefore, the applicant of the present invention has proposed an active distance measuring device capable of macro distance measurement in Japanese Patent Application No. 3-187643 as a camera equipped with this type of camera.

Further, an active distance measuring apparatus has already been proposed which enables APC (Auto Power Control) in which the light projection output is reduced by the intensity of light reflected from the subject.

[0004]

However, when an attempt is made to construct a combination of the above-mentioned conventional distance measuring devices (when a distance measuring device having a macro distance measuring function is added to an APC capable device). ), First, for aging of the light projecting means such as iRED, first energize so as to maximize the light projecting power, and reduce the light projecting power by the received light output of the reflected light reflected by the subject. Therefore, when the object is out of the distance measuring spot (where the light emitting spot hits) during distance measurement in macro mode, the light emitting means continues to emit light at maximum power, resulting in an increase in current consumption. There was a problem that it would end up.

Further, in the normal distance measurement of the distance measuring device capable of APC, the difference between the maximum light projection power and the normal light projection power is small, but in the macro distance measurement, the object is very close to the normal light projection power. Since it is very small, the difference between the maximum projection power and the normal projection power is large, and if iRED or the like is used as the projection means, the difference in the amount of heat generated by the difference in projection power causes a rapid thermal change in the element. However, there is a problem in that the light projection power is changed due to the light emission and the distance measurement accuracy is degraded.

Next, another problem will be described.

In the conventional active distance measuring device using the double integrating circuit, the integration time of a predetermined time is determined irrespective of the photometric value of the subject brightness in order to improve the distance measuring accuracy.

However, in the above-mentioned conventional example, the integration time is set long so as to sufficiently improve the distance measurement accuracy, and the integration time is set regardless of the photometric value of the subject luminance obtained by the photometric operation. Therefore, there is a problem in erroneous distance measurement due to camera shake or the like, and in quick shooting due to time loss.

Further, another problem will be described.

Conventionally, in a camera equipped with an active distance measuring device, when it is determined that the distance measuring information is closer than a certain distance, a short-distance warning is given, or a distance outside the photographing interlocking range of the photographing optical system is issued. It is widely known that an alarm is provided outside the interlocking range when it is determined that the distance is present, and a warning means for issuing a warning to the photographer is provided.

Further, means for dividing the long distance to the short distance into a plurality of zones, displaying the approximate distances in the zones based on the distance measurement information, and notifying the photographer of the distance measurement result Is also known.

However, among the above-mentioned conventional examples, the short-distance warning is a warning when a subject is close, and the out-of-interlocking range warning is a warning that there is a subject at a distance that cannot be photographed. It was not possible to combine these means with the means to warn of a void.

Further, in the case of the notification by the zone display, in order to display the hollow state, it is necessary to have a plurality of notification means and a means for selecting the notification means, which increases the cost. Control becomes complicated.

Further, in recent years, a multi-point distance measuring device for measuring a plurality of points on the screen has been proposed. In this type of device, generally, "middle void" (details will be described later with reference to FIG. 11). However, even if one of the multiple points measures the distance to the main subject, the distance data of the main subject cannot be selected depending on the distance relationship with other multiple points. In some cases, it is impossible to prevent the above-mentioned "middle-out" in the case of selecting data of a long distance.

A first object of the present invention is to provide a distance measuring device capable of suppressing useless projection output during distance measurement on the near side, saving current consumption, and preventing erroneous distance measurement. It is to be.

A second object of the present invention is to provide a camera capable of reducing the influence of a distance measurement error due to camera shake and the like, and further reducing the time loss to improve the quick-shooting property.

A third object of the present invention is to provide a camera capable of notifying a photographer of object distance information calculated for use during a photographing operation before the start of the photographing operation without increasing the cost of the camera. It is to be.

A fourth object of the present invention is to provide a camera capable of performing multi-point distance measurement and capable of issuing a warning that there is a possibility of "middle-out".

[0019]

According to the present invention, there is provided a projection output variable means for determining whether the selected range-finding range is the normal photographing range or the close-up side and changing the projection output based on this. When measuring the distance on the side, the light projection output is set lower (lower) than in the normal shooting range.

Further, there is provided integration time varying means for changing a predetermined time for integrating one output of the two kinds of signals from the light receiving means in accordance with the subject brightness obtained by the photometry means, and the subject brightness Accordingly, the integration time is changed, that is, the integration time is shortened when the subject brightness is bright.

Further, the notifying means for notifying that the distance information is farther than a predetermined distance within the interlocking range of the photographing lens and the distance information calculated by the distance measuring calculation means are notified by the notifying means. If it is distance information to determine whether or not it is information, to provide a notification control means for driving the notification means, if the calculated distance information is far from the predetermined distance , I am trying to announce that.

Further, at least one of the notification means and the plurality of pieces of distance measurement information is distance measurement information of a relatively short distance,
In the state where the remaining distance measurement information is farther than the distance measurement information, when the distance measurement means selects the far distance measurement information, a notification control means for driving the notification means is provided, and the distance measurement information is relatively short. When the distance measurement information and the distance measurement information are mixed and the distance measurement information of the far distance is selected as the final distance measurement information, the notification means is used to notify that effect. ..

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is a block diagram showing a schematic structure of a distance measuring device according to a first embodiment of the present invention. In FIG. 1, 1 is iRED which is a light projecting means, 2 is a transistor, and 3 is a resistor. Reference numeral 4 designates an operational amplifier constituting a constant current drive circuit of iRED 1, reference numerals 5 and 6 designate voltage dividing resistors for supplying a reference voltage of the ape amplifier 4 constituting the constant current drive circuit, 7
Is a DA converter.

Reference numeral 8 is a semiconductor position detecting device such as PSD, 9 is a distance measuring circuit using a well-known double integration circuit, and 11 is a switch for switching between macro distance measurement and normal distance measurement. 10
Is a microcomputer for detecting the state of the switch 11 and controlling the light emission output by the signal 12;
3, the distance measuring circuit 13 is controlled, and the distance measuring signal 14 from the distance measuring circuit 9 is input to calculate distance measuring information.

Next, the operation will be described with reference to the flowchart of FIG. "Step 1" It is determined from the state of the switch 11 whether the macro distance measurement or the normal distance measurement is performed. If the macro distance measurement is performed, the process proceeds to step 3, and if the normal distance measurement is performed, the process proceeds to step 2. "Step 2" Since it is normal distance measurement, here i
IRED current I so that the light projection power of RED1 becomes strong
_{Set iRED} to the larger one and proceed to step 4. "Step 3" Since it is macro distance measurement, iR is used here.
The iRED current I is adjusted so that the projection power of ED1 becomes weak.
_{Set iRED} to the smaller one and proceed to step 4. [Step 4] A known double integration or the like is performed to perform a distance measuring operation.

(Second Embodiment) FIG. 3 is a block diagram showing the schematic arrangement of a distance measuring apparatus according to the third embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals.

In FIG. 3, 15 is a reference voltage (Re
f), 16, 17, and 18 are voltage dividing resistors, which generate two different types of reference voltages. Reference numerals 19 and 20 are analog switches using FETs, 21 is an inverter, and 24 is a signal line for outputting a signal for controlling the analog switches 19 and 20.

Next, the operation will be described with reference to the flowchart of FIG. [Step 11] Whether the macro distance measurement or the normal distance measurement is performed is determined from the state of the switch 11. If the macro distance measurement is performed, the process proceeds to step 14, and if the normal distance measurement is performed, the process proceeds to step 12. "Step 12" Since normal distance measurement is being performed, the microcomputer 10 sets the signal line 24 to "L", the analog switch 20 to OFF, and the analog switch 19 to OFF.
Is turned on (because the output of the inverter 21 is "H"). As a result, the reference voltage of the operational amplifier 4, which is the constant current drive circuit, is set to a high level, and the iRED current I _iRED is set to a higher one so that the light projection power of the iRED 1 becomes stronger. "Step 13" Since the macro distance measurement is being performed, the microcomputer 10 sets the signal line 24 to "H", turns the analog switch 20 on, and turns the analog switch 19 on.
Set to FF. As a result, the reference voltage of the operational amplifier 4, which is the constant current drive circuit, is set to a low level, and the iRE
IRED current I _iRED so that the D1 projection power becomes weak
Is set to the lesser one. "Step 14" A known double integration or the like is performed to perform a distance measuring operation.

As described above, the projection power is changed by changing the output level of the signal line 24.

According to the first and second embodiments described above, the normal distance measurement or the macro distance measurement is discriminated, and the iR is determined based on the discrimination.
Since the projection power of the ED1 is changed, the projection power can be set according to the distance measurement distance. More specifically, during macro ranging, the projection power is set to a low value from the beginning because it is only close to the subject. Therefore, in macro ranging, the maximum projection power is reduced even when the focus spot deviates from the subject, and the power consumption is reduced. It is possible to save current.

Further, in the macro distance measurement, the light projection power is set to a weak one, so that the maximum light projection power is selected or the low light projection power is selected as in the prior art, and the light projection power is useless. The switching does not occur, and there is an effect that erroneous distance measurement due to heat generation of the light projecting unit can be prevented.

(Third Embodiment) FIG. 5 is a block diagram showing the schematic arrangement of a camera according to the third embodiment of the present invention.

In FIG. 5, 101 is a microcomputer for controlling the operation of each circuit, 102 is a switch (SW1) which is turned on by the first stroke of the shutter button, 10
3 is an external switch for switching whether or not to change the integration time, 104 is a photometric circuit, and 105 is a photometric sensor S.
PC, 106 is a distance measuring circuit, 107 is a PSD for a distance measuring light receiving element, 108 is a light receiving lens, 109 is a distance measuring light emitting element iRED, 110 is a light emitting lens, and 111 is a drive system circuit. ..

FIG. 6 is a circuit diagram showing a part of the light receiving portion in the distance measuring circuit 106 of FIG.

In FIG. 6, 118 and 119 are analog switches which can be switched by a signal from the microcomputer 101, 120 is a first stage amplifier, 121 is an amplifier, 122 is an integrator for performing double integration, and 123 is a reference voltage Vc and an integration. It is a comparator for comparing the voltage with the device 122, and the signal of the comparator 123 is sent to the microcomputer 101.

Next, the operation of the microcomputer 101 will be described with reference to the flowchart of FIG. "Step 31" It is determined whether or not the switch 102 (SW1) is turned on, and if it is turned on, step 32
Go to. [Step 32] It is determined whether or not the external switch 103 is turned on, and if it is turned on, the process proceeds to step 33 to start the distance measuring operation in the normal integration time.
If it remains F, the routine proceeds to step 42. "Step 33" The photometric circuit 104 is driven to perform a known photometric operation. Here "Step 34" to set the integration time to integration time T of the conventional (= t _1). [Step 35] Drive the distance measuring circuit 106 to perform iRED
Lighting of 109 is started. [Step 36] The light projected from the iRED 109 is reflected by the subject and received by the PSD 107. Here, the down integration of one output A of the PSD 107 is started. "Step 37" The timer in the microcomputer 101 is started. “Step 38” The count value T ′ of the timer is “t
_It is determined whether or not it has reached ₁ ”, and it is determined that it has reached (“ T ′ ≧
t ₁ )) to proceed to step 39. "Step 39" The timer is stopped. "Step 40" The iRED 109 is turned off, and the down integration of one output A of the PSD 107 is completed. As a result, the down integration of one output A of the PSD 107 is performed during the integration time t ₁ . "Step 41" Here, take a short break.

On the other hand, when it is determined in step 32 that the external switch 103 is turned on, the process proceeds to step 42 as described above. [Step 42] Similar to Step 33, the photometric circuit 104 is driven to perform a known photometric operation. "Step 43" The photometric value of the subject brightness obtained in step 42 is compared with a predetermined value set in advance. As a result, when it is determined that it is the "measured light value <specified value", the operation proceeds to the previous step 34 to initiate a distance measurement operation in the integration time of the conventional (T = t _1), "photometric If it is determined that “value ≧ predetermined value”, the process proceeds to step 44. Here "Step 44" is set to the integration time T "t _2" (provided that the relationship t ₂ <t _1). That is, when the subject brightness is higher than the predetermined brightness, the integration time is shortened. [Step 45] Driving the distance measuring circuit 106 to perform iRED
Lighting of 109 is started. "Step 46" The down integration of one output A of the PSD 107 is started. "Step 47" The timer in the microcomputer 101 is started. "Step 48" When the count value T'of the timer is "t
₂ "is determined, and it is determined that it has been reached (" T '≧
t ₂ )).

Thereafter, the above-mentioned steps 39 → 40 → 41
Are sequentially performed. As a result, during the integration time t ₂ , P
This means that the down integration of one output A of SD107 has been performed.

Next, the microcomputer 101 starts the operation from step 49. [Step 49] The distance measuring circuit 106 is driven to start the upward integration by the output (A + B) of the sum of both outputs A and B of the PSD 107, and the iRED 109 is turned on again. "Step 50" Start the timer. "Step 51" It is determined whether or not the output of the comparator 123 is inverted, and by inverting it, the integrated value of the output A by the down integration reaches the initial value by the up integration of the sum output (A + B). Then, the process proceeds to step 52. "Step 52" The timer is stopped. "Step 53" The iRED 109 is turned off, and the rising integration of the sum output (A + B) of the PSD 107 is completed. "Step 54" The count value of the timer is read. The count value here is t ₃ . "Step 55" The integration time T (t ₁ or t ₂ )
And the count t ₃ are used to calculate the distance measurement information by a known method. [Step 56] The lens barrel drive amount according to the distance measurement information is output to the drive system circuit 111 to drive the lens barrel to a predetermined position. "Step 57" A shutter control circuit (not shown) is driven to control opening / closing of the shutter based on the photometric value obtained in step 33 or 42. That is, the exposure operation on the film is performed. "Step 58" The lens barrel is driven to the initial position via the drive system circuit 111. "Step 59" The film is wound through the drive system circuit 111.

With the above, a series of photographing operations is completed.

(Fourth Embodiment) FIG. 8 is a flow chart showing the operation of the fourth embodiment of the present invention, which is different from the third embodiment in the following points.

That is, in this embodiment, the external switch 1
No. 03 is eliminated and the same result as above is obtained by comparing the photometric value obtained by the photometric operation with a predetermined value.
8 omits the operations of 2, 33.

In this embodiment, the integration time is one kind of “t ₂ ”, but the invention is not limited to this, and the integration time of several steps may be set corresponding to the photometric value which is the subject brightness. You can

According to the third and fourth embodiments described above, the integration time is set by comparing the photometric value, which is the subject brightness, with a predetermined value, that is, when the subject brightness is bright, the time setting for the down integration is conventionally set. Since it is set to a value shorter than the time, it is possible to reduce the influence of distance measurement error due to camera shake and the like, and it is possible to reduce the time loss and improve the quick-shooting property.

(Fifth Embodiment) FIG. 9 is a block diagram showing the schematic arrangement of a camera according to the fifth embodiment of the present invention.

In FIG. 9, 201 is a main CPU for controlling the operation of the camera, 202 is a drive circuit for driving iRED which is a light projecting means described later, and 203.
Is a light receiving circuit for processing a light receiving signal of the PSD 301, which is a light receiving means to be described later, 205 is a notification means for notifying that distance measurement has been performed, 206 is a switch (SW1) for preparing a shooting operation, and 207 is Release switch (S
W2), 208 is a photometric circuit for photometrically measuring the subject brightness, 20
9 is an exposure circuit for controlling the opening and closing of the shutter, 210 is a shooting lens drive circuit, 211 is a film feeding circuit, 212 is an AF focus notification LED, 300 is iRED, and 301 is P
SD, 302 is a light projecting lens, and 303 is a light receiving lens.

The operation of the above configuration will be described with reference to the flowchart of FIG. [Step 70] It is determined whether or not the switch SW1 is turned on, and if it is confirmed that the switch SW1 is turned on, the process proceeds to step 72. "Step 71" The photometric circuit 208 is driven to perform a known photometric operation. "Step 72" Light projecting circuit 202 and light receiving circuit 203
To perform a known distance measuring operation. [Step 73] It is determined whether or not the distance measurement information (AFDT) obtained in the above step 72 is shorter than a certain distance bm.
If it is determined that the distance is far, the process proceeds to step 75. "Step 74" 4H of LED 212 for AF focus notification
Flashes at z to announce that a short distance has been measured. Then, the process proceeds to step 78. [Step 75] This time, it is determined whether or not the distance measurement information AFDT is farther than a certain distance am (a> b), and if it is far, the process proceeds to step 76, and there is a relation of a>AFDT> b. If it is determined that the above, the process proceeds to step 77. “Step 76” Here, FIG.
The situation (c) is possible, so the notification means 2
It announces that it has driven the 05 and measured a long distance. Then, the process proceeds to step 77. “Step 77” Here, the AF focus notification LED 21
2 is turned on to notify that the distance measuring operation is completed. "Step 78" The state of the switch SW1 is discriminated again. If the switch SW1 remains on, the process proceeds to step 78, and if it is off, the process proceeds to step 79. [Step 79] The AF focus notification LED 212 is turned off, the notification of the long distance is canceled by the notification means 205, and the process returns to step 70. [Step 80] It is determined whether or not the release switch SW2 has been turned on, and if it remains off, step 78
Returning to step 81, when it is confirmed that it is turned on, the process proceeds to step 81. “Step 81” Here, as in step 79,
While turning off the AF focusing LED 212,
The notification of the long distance is canceled by the notification means 205, and the process proceeds to step 82. [Step 82] The lens drive circuit 210 is driven based on the distance measurement information AFDT to move the taking lens to a predetermined position. [Step 83] The exposure circuit 209 based on the photometric information (subject luminance information) obtained in step 71.
To control the opening and closing of the shutter. That is, the exposure operation is performed. [Step 84] The lens driving circuit 210 is driven to return the photographing lens to the initial position. "Step 85" The film feeding circuit 211 is driven to wind up the photographing frame. Then, the process returns to step 70 to prepare for the next shooting.

Here, FIG. 11 is a diagram for explaining the "middle gap" in the above distance measuring operation.

In FIG. 11, reference numeral 300 denotes iRED, which is the above-mentioned light projecting means, 301 is PSD, which is also the light receiving means, 302 is the same light projecting lens, and 30.
3 is a light-receiving lens, 304 is a main subject to be photographed, and 305 is an object farther than the main subject 304.

FIG. 11A shows the case where the distance is normally measured.
FIG. 11B shows a case where the light projected from the iRED 300 deviates from the main subject 304 and the object 305 on the far side is measured.
FIG. 11C shows the case where the light projected from the iRED 300 is out of the main subject 304 and the distance is measured as ∞ (infinity). Of these, FIG. 11B is shown.
And the case as shown in FIG. 11C is usually referred to as “middle-out”.

FIG. 12 shows the AF focusing LED 212 and the notification means 20 for making a long distance notification in the fifth embodiment.
5 is a diagram collectively showing operating states according to respective distance measurement information AFDT.

(Sixth Embodiment) FIG. 13 is a block diagram showing the schematic arrangement of a camera according to the sixth embodiment of the present invention. The same parts as those in FIG. 9 are designated by the same reference numerals.

FIG. 13 has a configuration in which the notifying means 205 for notifying that the long distance has been measured is omitted from the configuration of FIG. 9, and the long distance has been measured in comparison with the fifth embodiment. The notification is made to be displayed in a different manner by changing the display form of the AF focus notification LED 212.

The operation of the above configuration will be described with reference to the flowchart of FIG. "Step 91" It is determined whether or not the switch SW1 is turned on, and if it is confirmed that the switch SW1 is turned on, the process proceeds to step 72. "Step 92" The photometric circuit 208 is driven to perform a known photometric operation. “Step 93” Light projecting circuit 202 and light receiving circuit 203
To perform a known distance measuring operation. [Step 94] It is determined whether or not the distance measurement information (AFDT) obtained in the above step 94 is shorter than a certain distance bm. If it is determined that the distance is close (close), step 9 is performed.
If it is determined that the distance is far, the process proceeds to step 96. "Step 95" 4H for LED 212 for AF focus notification
Flashes at z to announce that a short distance has been measured. Then, the process proceeds to step 99. [Step 96] This time, it is determined whether or not the distance measurement information AFDT is longer than a certain distance am (a> b). If it is determined that the distance is longer than the distance am (a> b), the process proceeds to step 98, where a>AFDT> b. If it is determined to be true, the process proceeds to step 97. “Step 97” Here, in FIG.
Since the state (c) of (c) is possible, the AF focusing notification LED 212 is turned on to notify that the distance has been measured. Then, the process proceeds to step 99. "Step 98" Here, the AF focus notification LED 21
2 is flashed at 16 Hz (to differentiate from the notification of the short-range distance measurement field) to notify that the distance measurement operation is completed. [Step 99] The state of the switch SW1 is determined again. If the switch SW1 remains ON, the process proceeds to Step 101, and OFF.
If so, the process proceeds to step 100. [Step 100] The AF focus notification LED 212
Is turned off, and the process returns to step 91. [Step 101] It is determined whether or not the release switch SW2 has been turned on, and if it remains off, step 9
Returning to step 9 and confirming that it is turned on, step 102
Go to. [Step 102] Here, as in the previous step 100, the AF focus notification LED 212 is turned off, and the process proceeds to step 103. [Step 103] The lens drive circuit 210 is driven based on the distance measurement information AFDT to move the taking lens to a predetermined position. "Step 104" Based on the photometric information (subject luminance information) obtained in step 92, the exposure circuit 20
9 is driven to control the opening and closing of the shutter. That is, the exposure operation is performed. [Step 105] The lens driving circuit 210 is driven to return the photographing lens to the initial position. "Step 106" The film feeding circuit 211 is driven to wind up the photographing frame. Then, the process returns to step 91 to prepare for the next shooting.

FIG. 15 is a diagram collectively showing the operating state of the AF focusing LED 212 according to each distance measurement information AFDT in the sixth embodiment.

According to the fifth and sixth embodiments described above, when the long distance information is output, the photographer is notified to that effect, so that the photographer intentionally photographs the distant view. If you try to do so, the notification at this time will be a notification that the distance measurement is appropriate, while if you try to shoot a close-up view, you will be notified with a warning that the distance measurement is "middle-out" and fail. This has the effect of reducing the number of photos.

Further, since the notification is made only when the distance measurement information is far, it is necessary to select the notification means as compared with the structure in which the notification is made such that the main subject is on the short distance side or on the long distance side. It is a simple, low-priced warning that there is no problem. (Seventh Embodiment) FIG. 16 is a block diagram showing the schematic arrangement of a camera according to the seventh embodiment of the present invention. The same parts as those in FIGS. 9 and 13 are designated by the same reference numerals.

In FIG. 16, reference numeral 220 denotes a light projecting circuit for driving a plurality of light projected to be described later, 221 a light receiving circuit for performing a plurality of distance measurements, and 222 a light projecting means for emitting a plurality of light projected. IRED, 223 is a light receiving means for receiving a plurality of received lights, PSD is a light emitting lens, 224 is a light projecting lens, and 225 is a light receiving lens. It constitutes a multi-point range finder.

226 is a subject.

The operation of the above configuration will be described with reference to the flowchart of FIG. "Step 111" It is determined whether or not the switch SW1 is turned on, and if it is confirmed that it is turned on, step 11
Go to 2. "Step 112" The photometric circuit 208 is driven to perform a known photometric operation. “Step 113” Light projecting circuit 220 and light receiving circuit 22
1 is driven to perform the first distance measuring operation. [Step 114] Similarly, the light projecting circuit 220 and the light receiving circuit 221 are driven to perform the second and nth distance measuring operations. "Step 115" One of the most suitable distance measurement information is selected from the respective distance measurement information obtained in the first, second, and nth distance measurement. [Step 116] It is determined whether or not the distance measurement information (AFDT) obtained in the above step 115 is shorter than a certain distance bm. When it is determined that it is close (closest), the process proceeds to step 117, and it is determined that it is far. If step 11
Go to 8. [Step 117] 4 LEDs 212 for AF focus notification
Flashes at Hz to announce that a short distance has been measured. Then, the process proceeds to step 122. [Step 118] This time, it is determined whether or not the distance measurement information AFDT is farther than a certain distance am (a> b), and if it is far, the process proceeds to step 119, where a>AFDT>
If it is determined that the relationship of b is satisfied, the process proceeds to step 121. [Step 119] At least one of the other distance measurement information (AFDT ') not selected is the certain distance a.
It is determined whether or not the distance is closer than m. If it is determined that the distance is closer than m, the case as shown in FIG.
If a and AFDT '> a, the process proceeds to step 121. "Step 120" Here, the notification means 205 is driven to notify that the distance has been measured. Then, the process proceeds to step 121. "Step 121" Here, the AF focus notification LED 2
12 is turned on to notify that the distance measuring operation is completed. [Step 122] The state of the switch SW1 is determined again. If the switch SW1 remains on, the process proceeds to step 124 and off.
If so, the process proceeds to step 123. "Step 123" The LED 212 for informing the AF focus
Is turned off, the notification by the notification means 205 is canceled, and the process returns to step 111. “Step 124” It is determined whether or not the release switch SW2 is turned on, and if it is still off, step 1
Return to step 22 and confirm that it is turned on. Step 12
Go to 5. "Step 125" Here, as in the case of the previous step 123, the LED 212 for AF focus notification is turned off, the notification by the notification means 205 is canceled, and the step 1
Proceed to 26. [Step 126] The lens drive circuit 210 is driven based on the distance measurement information AFDT to move the photographing lens to a predetermined position. "Step 127" Based on the photometric information (subject luminance information) obtained in step 112, the exposure circuit 2
09 is driven to control opening / closing of the shutter. That is, the exposure operation is performed. [Step 128] The lens driving circuit 210 is driven to return the photographing lens to the initial position. "Step 129" The film feeding circuit 211 is driven to wind up the photographing frame. Then, step 111
Return to and prepare for the next shot.

Here, FIG. 18 shows that when a plurality of points are measured,
It is a diagram for explaining a case where long-distance information is output by "middle-out" except for one point, and the same portions as those in FIGS. 16 and 18 are denoted by the same reference numerals.

(Eighth Embodiment) FIG. 19 is a block diagram showing the schematic arrangement of a camera according to the eighth embodiment of the present invention. The same parts as those in FIG. 16 are designated by the same reference numerals.

FIG. 19 has a configuration in which the notifying means 205 for notifying that distance measurement has been performed is omitted from the configuration shown in FIG. 16, and in comparison with the seventh embodiment, distance measurement has been performed. The notification is made to be displayed in a different manner by changing the display form of the AF focus notification LED 212.

The operation of the above configuration will be described with reference to the flowchart of FIG. "Step 131" It is determined whether or not the switch SW1 is turned on, and if it is confirmed that it is turned on, then step 13
Go to 2. "Step 132" The photometric circuit 208 is driven to perform a known photometric operation. “Step 133” Light projecting circuit 220 and light receiving circuit 22
1 is driven to perform the first distance measuring operation. [Step 134] Similarly, the light projecting circuit 220 and the light receiving circuit 221 are driven to perform the second and nth distance measuring operations. [Step 135] One of the most suitable distance measurement information is selected from the respective distance measurement information obtained in the first, second, and nth distance measurement. [Step 136] It is determined whether or not the distance measurement information (AFDT) obtained in the above step 135 is shorter than a certain distance bm. When it is determined to be close (close), the process proceeds to step 137, and it is determined to be far. If step 13
Go to 8. “Step 137” 4 LEDs 212 for AF focus notification
Flashes at Hz to announce that a short distance has been measured. Then, the process proceeds to step 142. “Step 138” This time, it is determined whether or not the distance measurement information AFDT is longer than a certain distance am (a> b). If it is determined that the distance is longer, the process proceeds to step 139, and a>AFDT>
If it is determined that the relationship of b is satisfied, the process proceeds to step 141. [Step 139] At least one of the other distance measurement information (AFDT ') not selected is the certain distance a.
If it is determined that the distance is closer than m, and if it is determined that the distance is closer than m, the case as shown in FIG. 18 is conceivable, so proceed to step 140, and if it is determined that the distance is far, that is, AEDT> a and A
When FDT '> a, the process proceeds to step 141. "Step 140" Here, the AF focus notification LED 2
Flashes 12 at 16 Hz and announces that the distance has been measured. Then, the process proceeds to step 142. "Step 141" Here, the AF focus notification LED 2
12 is turned on to notify that the distance measuring operation is completed. [Step 142] The state of the switch SW1 is determined again, and if the switch SW1 remains on, the process proceeds to step 144 and off.
If so, the process proceeds to step 143. "Step 143" The AF focus notification LED 212
Is turned off, and the process returns to step 131. "Step 144" It is determined whether or not the release switch SW2 has been turned on, and if it remains off, step 1
When returning to 42 and confirming that it is turned on, step 14
Go to 5. [Step 145] Here, as in the case of the previous step 143, the AF focus notification LED 212 is turned off, and the process proceeds to step 146. [Step 146] The lens drive circuit 210 is driven based on the distance measurement information AFDT to move the photographing lens to a predetermined position. "Step 147" Based on the photometric information (subject luminance information) obtained in step 112, the exposure circuit 2
09 is driven to control opening / closing of the shutter. That is, the exposure operation is performed. "Step 148" The lens driving circuit 210 is driven to return the photographing lens to the initial position. "Step 149" The film feeding circuit 211 is driven to wind up the photographing frame. Then, step 131
Return to and prepare for the next shot.

According to the above seventh and eighth embodiments, the photographer using the camera having the multi-point distance measuring function is indifferent to the "middle-out", but
It is possible to give a warning that there is a possibility of "middle-out". Therefore, there is a high probability that proper shooting can be performed.

[0067]

As described above, according to the present invention,
Equipped with a projection output variable unit that determines whether the selected range-finding range is the normal shooting range or the close-up side and changes the projection output based on this. I try to lower the output.

Therefore, it is possible to suppress useless projection output during distance measurement on the closest side, save current consumption, and prevent erroneous distance measurement.

Further, there is provided integration time varying means for changing the predetermined time for integrating one of the two kinds of signals from the light receiving means in accordance with the subject brightness obtained by the photometric means, and the integration time varying means Accordingly, the integration time is changed, that is, the integration time is shortened when the subject brightness is bright.

Therefore, it is possible to reduce the influence of the distance measurement error due to camera shake and the like, and it is possible to reduce the time loss and improve the quick-shooting property.

Further, the notifying means for notifying that the distance information is farther than a predetermined distance within the interlocking range of the photographing lens and the distance information calculated by the distance measuring calculation means are notified by the notifying means. If it is distance information to determine whether or not it is information, to provide a notification control means for driving the notification means, if the calculated distance information is far from the predetermined distance , I am trying to announce that.

Therefore, it is possible to notify the photographer of the object distance information calculated to be used during the photographing operation before the start of the photographing operation without increasing the cost of the camera.

Further, at least one of the notification means and the plurality of pieces of distance measurement information is distance measurement information of a relatively short distance,
In the state where the remaining distance measurement information is farther than the distance measurement information, when the distance measurement means selects the far distance measurement information, a notification control means for driving the notification means is provided, and the distance measurement information is relatively short. When the distance measurement information and the distance measurement information are mixed and the distance measurement information of the far distance is selected as the final distance measurement information, the notification means is used to notify that effect. ..

Therefore, it becomes possible to issue a warning that there is a possibility of "middle-out" in a multi-point distance measuring device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a distance measuring device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a main part of the distance measuring device of FIG.

FIG. 3 is a block diagram showing a schematic configuration of a distance measuring device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of a main part of the distance measuring device of FIG.

FIG. 5 is a block diagram showing a schematic configuration of a camera of a third embodiment of the present invention.

6 is a circuit diagram showing a detailed configuration of the distance measuring circuit of FIG.

7 is a flowchart showing a series of operations of the camera of FIG.

FIG. 8 is a flowchart showing a series of operations of the camera of the fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a schematic configuration of a camera of a fifth embodiment of the present invention.

10 is a flowchart showing a series of operations of the camera of FIG.

11 is a diagram illustrating a case where a main subject is normally measured by the general range finding device arranged in the camera of FIG.
It is a figure for demonstrating the case where a state arises.

FIG. 12 is a diagram illustrating A for distance measurement information in the camera of FIG.
It is a figure which shows each operation state of LED for F focus notification, and a notification means.

FIG. 13 is a block diagram showing a schematic configuration of a camera according to a sixth embodiment of the present invention.

FIG. 14 is a flowchart showing a series of operations of the camera of FIG.

FIG. 15 is a diagram showing the operating state of each of the AF focus notification LED and notification means for distance measurement information in the camera of FIG. 13;

FIG. 16 is a block diagram showing a schematic configuration of a camera according to a seventh embodiment of the present invention.

FIG. 17 is a flowchart showing a series of operations of the camera of FIG.

FIG. 18 is a diagram for explaining a case where a “middle-out” state occurs in a general camera having a multipoint distance measuring function.

FIG. 19 is a block diagram showing a schematic configuration of a camera of an eighth embodiment of the present invention.

20 is a flowchart showing a series of operations of the camera of FIG.

[Explanation of symbols]

 1,109,222,300 iRED 2,107,223,301 PSD 4 operational amplifier 5,6,16,17 voltage dividing resistor 9,106 distance measuring circuit 10,101 microcomputer 103 external switch 201 main CPU 205 notification means 212 AF Focus notification LED

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication location G03B 7/26 9224-2K (72) Inventor Teruyuki Daimon 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A light projecting means for projecting light toward an object for distance measurement, a light receiving means for receiving reflected light of the projected light on the object for distance measurement, and distance measurement based on an output of the light receiving means. A distance measuring device having a distance calculating unit for calculating information and capable of performing distance measurement between a normal photographing range and a close-up side, determines whether the selected distance measuring range is a normal photographing range or a close-up side, and A distance measuring device comprising a projection output varying means for changing the projection output based on the above. 2. A light projecting means for projecting light toward a subject, a light receiving means for receiving reflected light of the projected light on the subject, and an output of one of two kinds of signals from the light receiving means. Is integrated for a predetermined time, then inversely integrated with two types of signals until reaching an initial value, and distance measurement calculation means for calculating distance measurement information from the relationship between the predetermined time and the time required for the inverse integration, and the subject brightness In a camera provided with a photometric means for measuring, an integration time for changing a predetermined time for integrating one output of the two kinds of signals from the light receiving means in accordance with the subject brightness obtained by the photometric means. A camera having variable means. 3. A camera provided with a light receiving means for receiving reflected light from a subject and a distance measuring calculation means for calculating distance information to the subject based on an output of the light receiving means, in a camera lens interlocking range. Of the distance information calculated by the distance measurement calculation means and the notification means for notifying that the distance information is longer than the predetermined distance, and determines whether or not the distance information calculated by the distance measurement calculation means is information to be notified by the notification means. If the distance information is to be notified, a camera is provided with notification control means for driving the notification means. 4. A distance measuring means for measuring a plurality of points on a photographing screen, selecting any one of the plurality of distance measuring information as distance measuring information, and making this the final distance measuring information. In the camera provided with, in the notification means and the plurality of distance measurement information,
In the state where at least one is relatively short distance measurement information and the rest is distance measurement information that is farther than the distance measurement information, when the distance measurement means selects the far distance measurement information,
A camera provided with notification control means for driving the notification means.