JPH0495937A - Autofocusing camera - Google Patents

Abstract

PURPOSE:To appropriately perform focusing by preventing the changing range of the focusing position of a photographing lens from being limited in the case that a remote control signal is transmitted from a 2nd range different from a 1st range. CONSTITUTION:In the case that the remote control signal is transmitted from the 1st range opposed to the front surface of a camera, photographing is performed by focusing on a specified distance even when distance information which is longer than the specified distance is outputted from an AF sensor. Meanwhile, in the case that distance information which is nearer to a short distance side than the specified distance is outputted from the AF sensor, photographing is performed based on the distance information. Namely, the changing range of the focusing position of the photographing lens is limited within a specified range which is nearer to the shortest distance than the specified distance. Thus, a picture where out-of-focus is little is taken.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic focusing camera capable of remote control photography.

C. Prior Art] So-called autofocus cameras, which detect the distance to a subject and automatically drive the photographic lens to the focusing position, are useful for photographers because they can take pictures without the complicated and troublesome operation of focusing. It's a very convenient camera. On the other hand, when photographing oneself using a self-timer or remote control device, the autofocus camera's distance measuring field of view, or distance measuring field of view, is narrow. If the camera is not positioned properly, there is a risk that the photo will be out of focus, for example, only the scenery in the background is in focus, and the real subject, the person, is out of focus.

Therefore, in Japanese Patent Application Laid-open No. 56-36632, the set position range of the photographing lens is limited during self-timer shooting to prevent the photographing lens from being driven to an inappropriate position as described above and resulting in out-of-focus photographs being taken. Means for prevention are disclosed.

[Problems to be Solved by the Invention] However, in addition to "remote control self-timer photography" in which you take pictures of yourself, there are other ways to remotely control photography using a remote control device, such as secret photography or as a substitute for a cable release. Therefore, the above-mentioned Japanese Patent Application Laid-Open No. 56-3663
If the setting distance range of the photographic lens is always limited as in No. 2, it is inconvenient for the photographer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in automatic focusing cameras that can be used for remote control photography. It is to provide a self-focusing camera.

[Means and effects for solving the problems] The automatic focusing camera of the present invention measures the object distance by receiving a remote control signal from the outside, and changes the focal position of the photographing lens based on this result. In an automatic focusing camera, when a remote control signal is transmitted from a first range that includes the optical axis of the photographic lens and faces the front surface of the camera, the range of change in the focal position of the photographic lens is limited to within a predetermined range. In addition, when a remote control signal is transmitted from a second range different from the first range, the range of change in the focal position of the photographing lens is not limited.

[Implementation example] The present invention will be explained below with reference to illustrated embodiments.

The present invention focuses on the fact that when photographing oneself using a remote control, the remote control operator, that is, the person to be photographed, is located in front of the camera, and the distance is approximately 1 to 5 meters. When a remote control signal is received from the first range facing the front of the camera, the change range of the focal position of the photographic lens is limited, and the second range other than the first range is When a remote control signal is received from within the range, the range of change in the focal position of the photographic lens is not limited. Therefore, before explaining the present invention in detail, its basic concept will be explained with reference to FIGS. 2 to 5.

FIG. 2 is a perspective view of a camera to which the present invention is applied. This camera body 1 includes a photographing lens 21. Release button 22.
Strobe 23. AF sensor 24° remote control signal reception window 2
5. Grip 26. A mode button 271 and display section 28 are provided respectively.

Two sets of sensors are provided in the remote control signal receiving section covered by the remote control signal receiving window 25. The parts of these two sets of sensors will be explained with reference to FIG.
lens 50 and second lens 5] respectively.

The function of these two sensors 52, 5B will be explained with reference to FIG. FIG. 4 shows the function of the sensor as seen from the top of the camera. The first range that can be received by the first sensor 52 is shown as remote control reception range A, and the second range that can be received by the first sensor 52 is
The second range where the remote control can be received is shown as the remote control reception range B. As can be seen from this figure, the first sensor 52
is activated by receiving a remote control signal from the front side of the camera, and the second sensor 53 receives a remote control signal from the rear side of the camera.

The operation of the camera configured in this way using a remote control will be described next. In FIG. 4, the mode button 27 provided on the top of the camera is operated to set the camera's operating mode to remote control mode. At this time, a display indicating the remote control mode is displayed on the display section 28 provided on the top surface of the camera. In this state, when the camera is released from the front using a remote control transmitter (not shown), this remote control signal is mainly received by the first sensor 52, which is a sensor on the front side of the remote control signal receiving window 25.

In this case, the relationship between the distance measurement field of view range and the photographing range with respect to the remote control signal reception range will be described below.

FIG. 5 is a diagram showing the relationship among the photographing range of the photographing lens, the distance measuring field of view of the AF sensor, and the reception range of the remote control signal, and for simplicity, only the front side of the camera is shown. In the figure, the shaded area is the distance measurement visual field range of the AF sensor, and its distance measurement angle is α. Also, 2 forming the angle β
Two-dot chain line Ω2. The area defined by ρ3 is the photographing range of the photographing lens. Furthermore, two 1s forming an angle γ
The area defined by the dotted chain line Ω42g5 and marked with a multi-dot pattern indicates the reception range of the remote control signal.

Here, the relationship between the receiving range of the remote control signal, the photographing range of the photographing lens, and the distance measuring range of the AF sensor at a position where the distance from the camera is L is that the δ and ε portions are the non-range measuring range, so If you try to take a picture of yourself using the remote control within this range of δ and ε, a distance measurement error will occur, and there is a high possibility that the picture will be out of focus.

By the way, the closer the distance from the camera is, the narrower the range of δ and ε is, so considering the size of a human being, it doesn't really matter much in practice, but the farther away from the camera, the narrower the range of δ and ε. Since δ and ε become wider, there is a higher possibility that a distance measurement error will occur. Considering the case where a photographer actually photographs himself/herself using a remote control, the value of the distance from the camera is approximately 1 m to 5 m. For example, if you set the distance limit for the distance from the camera (
(hereinafter referred to as the specific distance) is set to 5m, when shooting with this camera in remote control mode, even if the distance measurement data of the AF sensor outputs a distance longer than the specific distance of 5m, the subject Set the distance to that specific distance of 5m and take a picture.

With this configuration, there is practically no problem when using the remote control at short distances, and when using it at long distances, even if the camera is out of focus, it is possible to take a picture at an approximate distance, so it is not a problem. No photos can be taken. That is,
If the remote control signal is sent from the first range facing the front of the camera, even if the AF sensor outputs distance information that is longer than a certain distance, the camera will focus on this specific distance. Take a photo. On the other hand, if distance information on the shorter distance side than this specific distance is output from the AF sensor, a photograph is taken using that distance information. In other words, the range of change in the focal position of the photographic lens is limited to a predetermined range closer than the specific distance. With this configuration, it is possible to take photos that are less likely to be out of focus when operated from the front of the camera using the remote control.

Next, when a release operation is performed from the back of the camera using a remote control, this remote control signal is mainly transmitted to the second sensor 5, which is a sensor behind the remote control signal receiving window 25.
Received by 3. In this case, unlike when looking from the front of the camera, there is no specific distance limiter that limits the range of change in the focal position of the photographing lens within a predetermined range, and the lens is driven using the information measured by the AF sensor itself. Take a picture. This applies when using the remote control in place of a cable release or when taking hidden shots. That is, by fixing the camera on a tripod and operating the remote control from the back of the camera, the photographer can take pictures with less blur than by manually operating the camera's release button. You can also take pictures without the subject noticing.

In other words, it distinguishes whether the remote control is operated from the front of the camera or from the back, and automatically determines the purpose of use of the remote control and changes the control method, making operation extremely easy and convenient for the photographer. This allows you to take pictures that match your intentions. The above is the basic concept of the present invention. Next, one embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 6 to 9.

FIG. 6 is a block diagram of an automatic focusing camera showing an embodiment of the present invention, in which a control circuit 5 including a built-in CPU, etc.
The operation sequence of each part is controlled by First, when the remote control light receiving circuit 19 is selected by the control circuit 5, a release operation by remote control operation becomes possible. Then, when the remote control light projector 20, which will be described later in FIG.
filter) 19b, peak detection circuit 19c.

A first sensor 52 or a second sensor 53 connected to a remote control light receiving circuit 19 comprising a waveform shaping circuit 196 and the like.
receives the remote control signal light, shapes the waveform, and supplies it to the control circuit 5. Note that, as explained in FIGS. 3 and 4, the first sensor 52 includes the optical axis of the photographing lens,
The second sensor 53 is configured to receive a remote control signal projected from a first range facing the front of the camera.
It is adapted to receive a remote control signal projected mainly from a second range facing the rear surface of the camera, excluding the first range.

The control circuit 5 checks the light emission pattern and identifies whether the signal is from a remote controller or not. For example, if the light emission pattern is Nα1 in Table 1, which will be described later, the release is made after 3 seconds, or if the light emission pattern is No. 2, the release is made immediately.

In this way, when a release signal is received from the remote control light projector 20, a release process is performed.

Further, the control circuit 5 drives the light emitting element drive circuit 10,
A distance measuring light is projected from a distance measuring light projecting element 11 to a subject 13 via a light projecting lens 12 .

The distance measuring light reflected by the subject 13 is focused by a light receiving lens 14 and formed into an image on a light receiving surface of a PSD (semiconductor device detector) 15. A distance calculation circuit 16 calculates the photocurrent corresponding to the incident position on the PSD 15 to measure the distance to the subject. On the other hand, since the specific distance information explained in FIG. 5 is stored in the electrically erasable EEFROM 17, this specific distance information and the arithmetic circuit
A comparator circuit 18 compares the information with the distance measurement information obtained in step 1, and outputs the information to the control circuit 5. Note that the specific distance information stored in the EEPROM 17 can be rewritten at any time.

The control circuit 5 controls the zoom motor 2m to drive the zoom lens 2. The control circuit 5 also controls the shutter A
The F motor 4m is rotated in the normal direction to move the focus lens 3 to the in-focus position, and in response to this movement, the pulse train output from the pr (photo interrupter) 3a is counted. Further, after turning on the magnet 4a, the control circuit 5 reverses the shutter/AF motor 4m based on the photometric information obtained by the photometric circuit 7, and controls the aperture of the shutter 4. Then, when proper exposure is achieved, the magnet 4a is turned off to end the exposure. Furthermore, the control circuit 5 controls the upper iC! Based on the photometry output, if strobe light emission is necessary, the strobe circuit 8 is driven to emit strobe light. When the series of operations is completed, the winding motor 6 is driven to wind up the film.

FIG. 7 is a circuit diagram showing details of the remote control light projecting section 20 in FIG. 6 above. In the figure, a CPU 1101 performs light projection control, and it goes without saying that it may be constructed from a hard logic circuit such as a gate array. 1102.1
103.1104 is an external element for oscillation, and the CPU11
This is for generating the basic clock of 01. 1105 is a battery, 1
A diode 106 and a capacitor 1107 constitute a power filter to prevent the CPUll0I from malfunctioning even if a sudden voltage fluctuation occurs in the light source voltage during IRED light emission.

1108.1110.1111 is resistance, 1109°11
12 is a transistor; when CPUll0I outputs a light emission signal, transistors 1109 and 1112 are turned on;
The IREDs 1113 and 1114 emit light. In this case, two are used in parallel to increase the amount of light emitted, but of course two
It may be more than one. 1115 is a capacitor, IR
Supplements the light source during ED light emission. SWl is a start switch, and when this switch is turned on, CPUll0I starts light emission operation. SW2. SW3 is a mode switch, and as described later, the light emission pattern changes depending on the combination of these two switches. The camera then identifies that pattern and performs the corresponding action.

Figure 8 is a pattern diagram of the output pulses output from the terminals "OUT" of cpr and rxioi, and Figure 9 is the first one.
It is an enlarged view of the pulse group TW, -TW4. In the figure, time T1. T2. TW1 to TW4 with an interval of T3
The pulse with a time width of is the carrier frequency f c -35,7
It is output on KHz. The time relationship between these constituent pulses is as shown in FIG. And T1~
T3 is the mode switch SW2. in FIG. 7 above. Depending on the on/off combination of sw3, the time width is set as shown in Table 1 below.

Table 1 The operation of the release process in this embodiment configured as described above will be explained with reference to the flowchart shown in FIG. When this flow starts, photometry and distance measurement are first performed (steps S1 and S2), and then it is checked whether or not the self-remote control mode is set (step S3). If it is not the self-remote control mode, the control circuit 5 performs normal operation of the release switch 9 and jumps to step SIO. On the other hand, in the self-remote control mode, the first and second sensors 52. It is checked whether or not remote control light reception by 53 has been performed (step S4).

If the remote control light is not received, the release is performed by the release switch 9 in the remote control mode, so a self-timer operation is performed (step S5).

On the other hand, if the remote control light is received, it is determined whether the light is received by the first sensor or the second sensor (step S6).

If the remote control light reception is by the second sensor, the process immediately advances to step S10 to perform a normal AF operation based on normal ranging data. On the other hand, if the remote control light reception is by the first sensor, the EEFR that stores specific distance information
The stored information L2 of the OM 17 (see FIG. 6) is read out (step S7) and compared with the object distance information L1 measured in step S2 (step S8). And Ll>
If it is L2, the measured distance is beyond a certain distance, for example, 5m as explained in Figure 5 above, so there is a possibility that the distance was measured not to the main subject, but to the background. Therefore, the AF operation is performed using the specific distance L2 stored in the EEFROM as the subject distance. On the other hand, if L1≦L2, use the distance measurement data as is (step 5IO
) Performs AF operation.

In step Sll, the number of pulses for advancing the photographic lens is calculated based on the distance information obtained in step S9 or step SIO, and based on the calculated value,
The photographic lens is extended (step 512), and an exposure operation is performed (step 813). In this case, if the subject is dark or backlit, strobe light is emitted, but the Flashmatic calculation at this time is determined by the output of the comparison circuit 18 in step S8. Of course, it is calculated based on the distance of . After the exposure is completed, the winding motor 6 is driven to wind the film (step 514), and the end is reached.

In the above embodiment, the remote control signal receiving sensors are installed facing the front and back of the camera, but the sensors facing the back may be installed facing toward the side of the camera. In this way, the remote control from the side of the camera can be used in place of the cable release.

Furthermore, the receiving ranges of the sensors fixed facing the front and back may be changed as appropriate. With this configuration, the sensitivity range of the front-facing sensor can be matched to the shooting range of the camera and the distance measurement range of the AF sensor, and the sensor fixed to the back can cover a wider area of the back of the camera. By doing so, the remote control can be used in place of a cable release in a wider range.

In the above embodiment, when a remote control signal is transmitted from the first range facing the front of the camera, the distance is limited to a specific distance even if the distance measurement output information indicates a distance longer than the specific distance. However, the specific distance in this case was a fixed value. However, this specific distance may not be a fixed value, but may be changed in accordance with the focal length of the photographing lens, and such a first modification will be explained below with reference to FIG. 10.11.

Figure 10 is a diagram in which the focal length of the photographing lens is plotted on the vertical axis and the reciprocal of the object distance is plotted on the horizontal axis. Of the areas divided into two, the nearer area (I) is photographed using the subject distance measured by the AF sensor, and the far side area (n) is photographed using the subject distance indicated by curve g1. be done. That is, when a camera with a focal length of X takes a picture of a subject with a subject distance of LX2, the picture is actually taken at LX2, but when a subject with a subject distance of LXl is pictured, the picture is taken with LX.

It will be photographed in In addition, LT and LW are tele (T) of curve g1
The subject distances at the end and wide (W) end are shown.

FIG. 11 is a block configuration diagram showing the circuit configuration at this time. The difference between FIG. 11 and FIG. 6 is that the zoom encoder 2a outputs the focal length information of the photographing lens.
Except for this point, there is no difference from FIG. 6 above.

Therefore, the same constituent members are given the same reference numerals and their explanations will be omitted. Then, based on the information of the zoom encoder 2a that outputs focal length information of the photographing lens, the subject distance at this focal length is detected from the EEPROM 17, which serves as a fixed distance information memory and stores information corresponding to the curve g1 in FIG. 10. By comparing this distance with distance information from the distance calculation circuit 16, the amount of lens extension is controlled.

With this configuration, the long focal length side (T side), which is the typical use of a zoom lens, positions the subject at a far distance, while the short focal length side (W side) positions the subject at a close distance side. This allows you to take photos that are least out of focus, in response to the situation where you are often located at

In the above embodiments and modifications, the first sensor receives the remote control signal transmitted from the range Ml, and the second sensor receives the remote control signal transmitted from the second range.
Although two sensors were used, it is also possible to use one sensor. Such a second modification will be explained below with reference to FIGS. 12 to 14.

In the figure, a rotatable sensor 3 is mounted on the top of the camera body 1.
1 is provided so that its rotational position can be detected by the encoder pattern 32 and the contact pieces 33a to 33d. For example, if the sensor is in the receiving range ■ in Figure 12, contact piece 3
3a and 33b are conductive, and the rest of the receiving range (2) is non-conductive, so that the direction in which the sensor is facing can be determined. Therefore, if the above-mentioned distance restriction is performed when the sensor is within the reception range (2), but not when the sensor is within the reception range (2), there is no need to prepare two sensors.

According to the above embodiment, when taking pictures using a normal remote control, it is common to take pictures at a distance of 1 m to 5 m, and it is very rare to take pictures at a distance longer than this. Therefore, AF at a distance longer than this specific distance
With a very simple configuration in which all sensor information is set to a specific distance, you can take photos that are less likely to be out of focus.

In addition, by receiving remote control signals from two directions, you can take photos with less out of focus as described above, and at the same time, by operating from a specific direction of the camera, it can be used in place of a cable release, so you can use the remote control. The purpose will further expand and the benefits for users will expand.

[Effects of the Invention] As described above, according to the present invention, when a remote control signal is transmitted from the first range that includes the optical axis of the photographic lens and faces the front surface of the camera, the focal point of the photographic lens is In addition to limiting the range of change in the position within a predetermined range, if the remote control signal is transmitted from a second range different from the first range, the range of change in the focal position of the photographing lens is not limited. Therefore, a remarkable effect is achieved in that the camera can focus on the subject intended by the photographer depending on the purpose of using the remote control.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of the release processing operation in an autofocus camera according to an embodiment of the present invention. FIG. 2 is a perspective view of an autofocus camera to which the present invention is applied. FIG. 2 is a perspective view of the sensor in FIG. 2; FIG. 4 is a plan view of the camera showing the function of the sensor shown in FIG. 3; FIG. 5 is a photographic range of the photographing lens in FIG.
FIG. 6 is a block configuration diagram of an automatic focusing camera showing an embodiment of the present invention; FIG. FIG. 8 is a pattern diagram of the output pulses output from the CPU in FIG. 7 above. FIG. 9 is an enlarged view of one group of pulses in FIG. 8 above. Figure 10 is a diagram plotting the focal length of the photographic lens corresponding to the reciprocal of the object distance in the first modification of this embodiment, and Figure 11 is the first modification shown in Figure 10 above. FIG. 12 is a plan view of a camera according to a second modification of the present embodiment. FIGS. 13 and 14 are diagrams showing the relationship between the encoder pattern and the contact piece in FIG. 12.

Claims (1)

[Claims] (1) In an automatic focusing camera that receives an external remote control signal, measures the subject distance, and changes the focal position of the photographic lens based on this result, the distance that includes the optical axis of the photographic lens and the front of the camera. The first one facing
If the remote control signal is transmitted from a range, the change range of the focal position of the photographing lens is limited to within a predetermined range, and the remote control signal is transmitted from a second range different from the first range. In this case, an automatic focusing camera characterized in that the range of change in the focal position of the photographing lens is not limited.