JP4688485B2 - Imaging device with auxiliary light function - Google Patents

Description

  The present invention relates to an imaging device such as a silver salt camera, a digital camera, or a portable information input device having an auxiliary light function.

In a two-stage SW type release operation in a conventional autofocus camera, half-press (first stage) performs AF (distance measurement), AF result display and focusing, and full-press (second stage) exposes (shutter control). ) Is a common shutter sequence. In the case of a camera with an auxiliary light function, light is emitted simultaneously with the AF operation when half-pressed. However, there is a problem in that when the subject is photographed at the time of half-pressing and the AF operation is performed, if the subject to be photographed is a person, the auxiliary light is emitted when half-pressed, so that it is misunderstood that the subject was photographed at that time. there were. This is especially true when the auxiliary light is also used with a strobe. In addition, these cameras have problems such as shortening the battery life because auxiliary light is emitted each time the camera is half-pressed. As a conventional technique for automatically measuring an object distance during a shutter operation and driving a photographing lens to a focus position, an “autofocus camera” described in Patent Document 1 is known. As a conventional technique for adjusting the amount of light emission according to the subject distance, a “photographing illumination device” described in Patent Document 2 is known. As a technique for performing focus detection by irradiation of an auxiliary illumination device, an “auxiliary illumination device for an autofocus camera” described in Patent Document 3 is known. As an autofocus camera provided with a flash device that projects auxiliary light onto a subject, an “autofocus camera” described in Patent Document 4 is known.
Japanese Utility Model Publication No. 7-22648 JP 2002-207236 A Japanese Patent No. 2691206 Japanese Patent No. 2709375

  Accordingly, the present invention has been made to solve the above-described problems, and eliminates a sense of incongruity about light emission on the side to be photographed, and also has an auxiliary light function imaging device that does not shorten the battery life. The purpose was to provide.

In order to solve the above problems, the present invention provides a photographing operation member having a two-step operation position of half-pressing and full-pressing, a distance measuring unit based on a triangulation or phase difference detection method for measuring a distance from a subject, Reliability determination means for determining reliability based on a distance measurement result of the distance measurement means; focus adjustment position calculation means for calculating a focus adjustment position based on the distance measurement result of the distance measurement means; and the focus adjustment position a focus adjustment control means for focusing based on a calculation result of the calculating means, the auxiliary Johikari function imaging apparatus having an auxiliary light irradiating means for irradiating an auxiliary light to the subject, an exposure control means for performing exposure, An auxiliary light determining unit that determines whether auxiliary light is necessary, and when the photographing operation member is in a half-pressed state, the auxiliary light determining unit performs the determination and determines that auxiliary light is necessary; Auxiliary light by light irradiation means Without performing illumination and focusing by the focus adjustment control means, wherein when the full press of the photographing operation member, wherein by irradiating auxiliary light by the auxiliary light emitting means, implemented Rihaka distance by the distance measuring means , the distance measuring result the focusing position calculating means based on the calculates the focusing position, the focus adjustment control means based on said focus adjusting position after focus adjustment control, said exposure control means to implement exposure It is characterized by.
Here, a strobe, LED, or lamp can be used as the auxiliary light irradiation means.
The auxiliary light determining means preferably determines that auxiliary light is necessary when the reliability determining means determines that the reliability is low.
Further, it is preferable that the auxiliary light determining means determines that auxiliary light is necessary when the subject environment has low luminance.
Still further, it is preferable that the auxiliary light determining means determines that auxiliary light is necessary when the subject environment is in a backlight state.
The focus adjustment is performed when it is determined that the reliability is low by the determination of the reliability determination unit based on the distance measurement result that is irradiated with the auxiliary light when the photographing operation member is fully pressed and is measured by the distance measurement unit. The control means can perform the focus adjustment control with the focus adjustment position as a fixed position. Here, the fixed position is preferably an ordinary focal length position.

  As described above, according to the present invention, when it is determined that auxiliary light is necessary when the imaging operation is half-pressed, the re-ranging and focusing operation by the auxiliary light is prohibited when half-pressed, and the auxiliary light is pressed when fully pressed. By performing the re-ranging and focusing operation by, the sense of discomfort due to the light emission when half-pressed, that is, the misunderstanding that it was taken, is eliminated, and the unnecessary light emission when half-pressed is eliminated, The effect of extending the life is obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the code | symbol of each figure has attached | subjected the same code | symbol regarding the same member and the same process.
1 is a top view of a digital camera when the present invention is applied to the digital camera, FIG. 2 is a front view of the digital camera of FIG. 1, and FIG. 3 is a back view of the digital camera of FIG. FIG. 4 is a block diagram of the digital camera of FIG. 1 to 3, a release shutter SW1, a mode dial SW2, and a sub LCD (liquid crystal display) 1 are disposed on the top surface of the digital camera.

  On the front side of the digital camera, an SD card / battery cover 2, a strobe light emitting unit 3, an optical viewfinder 4, a distance measuring unit (external AF unit) 5, a remote control light receiving unit 6, and a lens barrel unit 7 are arranged. On the back side of the digital camera, an AF LED 8, a strobe LED 9, an LCD monitor 10, a zoom switch (wide) SW3, a zoom switch (far / near) SW4, a self-timer / delete switch SW5, and a menu switch SW6 are arranged. On the back of the digital camera, an up / strobe switch SW7, a right switch SW8, a display switch SW9, a down / macro switch SW10, a left / image confirmation switch SW11, an okay switch SW12, and a power switch SW13 are arranged.

  Next, the operation of the digital camera according to the present invention will be described with reference to FIGS. The lens barrel unit 7 includes a zoom lens 7-1a for capturing an optical image of a subject, a zoom optical system 7-1 including a zoom drive motor 7-1b, a focus optical system including a focus lens 7-2a, and a focus drive motor 7-2b. 7-2. The lens barrel unit 7 includes an aperture unit 7-3 including an aperture 7-3a and an aperture motor 7-3b, a mechanical shutter unit 7-4 including a mechanical shutter 7-4a, and a mechanical shutter motor 7-4b. A motor driver 7-5 for driving each motor is provided.

The motor driver 7-5 receives a drive command from a CPU block 104-3 in the digital still camera processor 104 (to be described later) based on an input from the remote control light receiving unit 6 or an operation input from the operation unit key unit (SW1 to SW13). The drive is controlled by.
The ROM 108 stores a control program and parameters for control, which are described in codes readable by the CPU block 104-3. When the power of the digital camera is turned on, the program is loaded into a main memory (not shown), and the CPU block 104-3 controls the operation of each part of the apparatus according to the program.

Data necessary for control and the like are temporarily stored in the RAM 107 and a local SRAM 104-4 in the digital still camera processor 104 described later. By using a rewritable flash ROM for the ROM 108, the control program and parameters for control can be changed, and the function version can be easily upgraded (VerUp).
The CCD 101 is a solid-state imaging device for photoelectrically converting an optical image. The F / E (front end) -IC 102 is a CDS 102-1 that performs correlated double sampling for removing image noise, an ADC 102-2 that performs gain adjustment, and a digital signal. An A / D 102-3 that performs conversion is included.

The F / E (front end) -IC 102 is further supplied with a vertical synchronizing signal (hereinafter referred to as VD) and a horizontal synchronizing signal (hereinafter referred to as HD) from the CCD1 control block 104-1, and the CPU block 104-3. TG 102-4 that generates drive timing signals for the CCD 101 and the F / E-IC 102 controlled by the above.
The digital still camera processor 104 performs white balance setting and gamma setting on the output data of the F / E-IC 102 from the CCD 101, and as described above, the CCD1 control block 104-1 for supplying the VD signal and HD signal, the filtering It has a CCD2 control block 104-2 that performs conversion into luminance data and color difference data by processing.

Further, the digital still camera processor 104 is connected to an external device such as a CPU block 104-3 for controlling the operation of each unit described above, a local SRAM 104-4 for temporarily storing the data necessary for the control described above, a personal computer, and the like. A USB block 104-5 for performing USB communication and a serial block 104-6 for performing serial communication with an external device such as a personal computer are included.
In addition, the digital still camera processor 104 includes a JPEG CODEC block 104-7 that performs JPEG compression / decompression, a resize block 104-8 that expands / reduces the size of image data by interpolation processing, and displays image data on an external display such as a liquid crystal monitor or TV. It has a TV signal display block 104-9 for converting it into a video signal for display on a device, and a memory card block 104-10 for controlling a memory card for recording photographed image data.

The SDRAM 103 temporarily stores image data when the digital still camera processor 104 performs various processes on the image data.
For example, the stored image data is acquired from the CCD 101 via the F / E-IC 102 and “RAW-” in a state where white balance setting and gamma setting are performed in the CCD 1 signal processing (control) block 104-1. RGB image data ”,“ YUV image data ”in which luminance data / color difference data conversion has been performed by the CCD2 control block 104-2,“ JPEG image data ”compressed by JPEG by the JPEGCODEC block 104-7, and the like.

The memory card throttle 121 is a throttle for mounting a removable memory card 124. The built-in memory 120 is a memory for storing captured image data even when the memory card 124 is not attached to the memory card throttle 121 described above.
The LCD driver 111 is a drive circuit that drives the LCD monitor 10 described later, and also has a function of converting the video signal output from the TV signal display block 104-9 into a signal to be displayed on the LCD monitor 10. .

The LCD monitor 10 is a monitor for monitoring the state of a subject before shooting, confirming a shot image, displaying image data recorded in the memory card 124 or the built-in memory 120 described above, and the like.
The video AMP 118 is an amplifier for converting the impedance of the video signal output from the TV signal display block 104-9 to 75Ω, and the video jack 119 is a jack for connecting to an external display device such as a TV. The USB connector 122 is a connector for performing USB connection with an external device such as a personal computer.

The serial driver circuit 123-1 is a circuit for converting the output signal of the serial block 104-6 described above in order to perform serial communication with an external device such as a personal computer. The RS-232C connector 123-2 is a personal computer. This is a connector for serial connection with external devices such as.
The sub-CPU 109 is a CPU in which ROM / RAM is built in one chip, and outputs the output signals of the operation key units (SW1 to SW13) and the remote control light receiving unit 6 to the CPU block 104-3 described above as user operation information. The camera state output from the CPU block 104-3 is converted into control signals for the sub LCD 1, AF LED 8, strobe LED 9, and buzzer 113, which will be described later, and output.

The sub LCD 1 is a display unit for displaying, for example, the number of shootable images, and the LCD driver 111 is a drive circuit for driving the sub LCD 1 described above based on the output signal of the sub-CPU 109 described above.
The AF LED 8 is an LED for displaying a focus state at the time of photographing, and the strobe LED 9 is an LED for indicating a strobe charging state. The AF LED 8 and the strobe LED 9 may be used for another display application such as when a memory card is being accessed.

The operation key units (SW1 to SW13) are key circuits operated by the user, and the remote control light receiving unit 6 is a signal reception unit of the remote control transmitter operated by the user.
The voice recording unit 115 includes a microphone 115-3 for inputting a voice signal by a user, a microphone AMP 115-2 for amplifying the input voice signal, and a voice recording circuit 115-1 for recording the amplified voice signal.
The audio reproduction unit 116 converts an audio reproduction circuit 116-1 that converts a recorded audio signal into a signal that can be output from a speaker, an audio AMP 116-2 that amplifies the converted audio signal, and drives the speaker, and an audio signal. The output speaker 116-3 is provided.

Next, a description of the external AF unit 5 and a re-ranging calculation method and a re-ranging determination method using the external AF unit 5 will be given.
First, the structure and calculation method of the external AF unit 5 will be described.
FIG. 5 is a diagram showing the configuration of the external AF unit 5.
The distance measuring element includes a light receiving sensor 11 that receives light from an incident subject, a distance measuring element control unit 12, a lens 13 that forms an image of light from the subject on the light receiving sensor 11, and an amount of light incident on the light receiving sensor 11. The aperture 14 is configured to limit

The light receiving sensor 11 is divided into a right light receiving sensor 11-1 and a left light receiving sensor 11-2 which are separated by a center interval B. The left and right light receiving sensors have a plurality of light receiving elements of the same number on the left and right, and the light receiving elements are arranged in a line.
The distance measuring element control unit 12 stores a program for controlling the accumulation of the light receiving sensors and the reading of the amount of light received by each light receiving element.

FIG. 6 is a diagram showing the operating principle of the distance measuring element used in the present invention.
In FIG. 6, the distance to the subject is L, the distance between the left and right lenses and the light receiving sensor is f, and the right lens 13-1, the right light receiving sensor 11-1, the left lens 13-2, and the left light receiving sensor 11-2 are associated. The distance between the light receiving elements to be measured is B, and the optical axis deviation amounts of the light incident on the right light receiving sensor 11-1 and the left light receiving sensor 11-2 and the parallel light (light from infinity) are X1 and X2, respectively. The distance L from the center position perpendicular to the optical axis direction of the lens of the distance element to the subject is calculated by the following formula using the triangulation method.

L = B · f / (X1 + X2) (1)
Since the distance B between the light receiving sensors and the distance f between the lens and the light receiving sensor are values determined in advance by the distance measuring element, the CPU reads the light receiving amount of the light receiving sensor of the distance measuring element, and from the read light receiving amount By calculating (X1 + X2) and substituting the calculated (X1 + X2) into the above equation (1), the distance L to the subject can be calculated.

FIG. 7 is a diagram illustrating a light receiving area of the light receiving sensor.
As described above, the light receiving sensor 11 has the same number of light receiving elements on the left and right.
The plurality of light receiving elements are grouped into a plurality of light receiving areas by combining a predetermined number of light receiving elements into one light receiving area.
The light receiving elements included in each light receiving area may overlap another plurality of areas.

  For example, the left and right light receiving sensors are each composed of 130 light receiving elements, and if one light receiving area is composed of 30 light receiving elements, the first to 30th light receiving elements from the left end are the light receiving area 1, The 20th to 50th light receiving elements are the light receiving area 2, the 40th to 70th light receiving elements are the light receiving area 3, the 60th to 90th light receiving elements are the light receiving area 4, and the 80th to 110th light receiving elements. The light receiving area 5 is the light receiving area 5, and the 90 to 130 th light receiving elements are the light receiving area 6.

In this case, ten light receiving elements are overlapped from the left end of each light receiving area.
As shown in FIG. 7, the light receiving area is divided in the same way for the left and right light receiving sensors, so that the light receiving areas are divided into corresponding light receiving areas on the left and right.
The distance L to the subject is calculated for each light receiving area.

FIG. 8 is a diagram for explaining received light data received in each light receiving area.
The vertical axis represents the magnitude (light quantity) of received light data received by the light receiving elements in the light receiving area, and the horizontal axis represents the position of each light receiving element.
(X1 + X2) is obtained by comparing the shape of the light reception data in the left and right light reception areas and detecting how much the shape of the light reception data is shifted.

FIG. 9 is a diagram illustrating the contrast prescribed value of the received light data.
The vertical and horizontal axes are the same as in FIG.
When the difference between the maximum value and the minimum value of the received light data in the light receiving area is less than the specified value, it is determined as contrast determination NG. It is determined whether each of the corresponding left and right light receiving areas is greater than or equal to a specified value.

FIG. 10 is a diagram for explaining the left-right image difference of the received light data.
The vertical and horizontal axes are the same as in FIG.
The light reception data in the left and right light reception areas should ideally have the same shape in the vertical axis direction. However, depending on the condition of the subject light, the shape may be different in the vertical axis direction.
Therefore, the left and right image difference determination is performed by comparing the total amount of light received by all the light receiving elements in the light receiving area.
The area surrounded by the straight line indicating the total received light amount of the right sensor and the broken line indicating the total received light amount of the left sensor shown in FIG. 10 is the difference in the total received light amount of the left and right sensors.
If this value is greater than or equal to a predetermined value, the left / right image difference determination is NG.

  When a light receiving command is sent from the control unit 12 of the external AF unit 5, the left and right light receiving sensors receive light according to the charge accumulation mode of the external AF unit 5. This charge accumulation mode determines the light receiving method of the light receiving sensor in the external AF unit, and there are two modes, an automatic accumulation mode and a forced accumulation mode.

  The automatic accumulation mode is a mode that automatically ends when there is at least one light receiving sensor that receives a certain amount of light. The elapsed time at this time is defined as the charge accumulation time. In the forced accumulation mode, light is received until a preset charge accumulation time. Usually, in this charge accumulation mode, light is received in the automatic integration mode. When this light reception is completed, the correlation between the left and right subject images in each area of the light receiving sensor is detected, and the deviation amount of the left and right light receiving elements is calculated based on the detected correlation value. From the calculated deviation amount, the distance to the subject is calculated using triangulation, and this is used as a distance measurement value.

  Accordingly, each area has a different distance measurement value (distance data). Actually, the distance measurement value from the external AF unit that is output to the camera side and its area are the same as the distance measurement value of each area closer to the other area, and the reliability of the sensor data received in that area. It is determined by judging whether it is high. The determination of the reliability of the sensor data is performed based on whether or not the contrast of the received light data in the left and right areas, the left and right image difference, etc. satisfy the specified values. However, when all the areas do not satisfy the specified value, an area having the highest reliability of the distance measurement value (closest to the specified value) is selected from all the areas.

The flowchart shown in FIG. 11 is an AF distance measuring method in the present invention using the configuration and calculation method of the external AF unit 5. With respect to FIG. 11, the configuration and calculation method of the external AF unit 5 and the results of re-ranging calculation processing (FIG. 12) and re-ranging determination processing (FIG. 13) described later are reflected (charge accumulation mode). Determination, strobe auxiliary light flag), and distance measurement. First, a series of flows related to FIG. 11 will be described.
First, it is determined whether or not the charge accumulation mode is the automatic accumulation mode for the light received by the external AF unit 5 (5-1). If it is the automatic accumulation mode, the process proceeds to the next process, and if it is the forced accumulation mode, the charge accumulation time is set (5-2). The setting of the charge accumulation time is the charge accumulation time set in the re-ranging determination process (FIG. 13) described later.

Next, it is determined whether or not the strobe auxiliary light flag is ON (5-3). This strobe auxiliary light flag is determined by turning on / off the strobe auxiliary light flag in a re-ranging determination process (FIG. 13) described later. If the strobe auxiliary light flag is ON, processing (5-4) is performed to prepare a strobe so that strobe light can be emitted at the time of light reception. Otherwise, light reception processing is started.
Next, the light beam of the subject is received by the charge storage type light receiving element by the light receiving process (5-5). If the strobe auxiliary light flag is ON from (5-3), light is emitted for a predetermined light emission time during light reception. The predetermined time indicates the amount of light that the strobe can reach up to a certain distance (approximately 5 m), and is fixed (10 μs) here. However, since the setting of the light emission time depends on the performance of the strobe unit, it may be variable.

  Next, a distance measurement value is calculated by a distance calculation process (5-6). The calculation method is as described for the configuration of the external AF unit 5 and the calculation method. Next, out of the distance measurement values for each area calculated in the previous process by the distance measurement determination process (5-7), the distance of the area considered to be highly reliable is output as a distance measurement value. The selected area is also output (5-8). The above is the description regarding the AF distance measuring method of FIG.

  Next, the re-ranging calculation process in FIG. 12 will be described. First, the first distance measurement is started (6-1). The first distance measurement is performed according to the flow of the AF distance measurement method in FIG. For the first distance measurement, the charge accumulation mode is set to the automatic accumulation mode, and the strobe auxiliary light flag is OFF. Next, in the re-ranging determination, the reliability of the distance measurement value of the selected area is determined (6-2). The details are performed by a re-ranging determination process according to FIG. 13 described later. Next, it is determined whether or not the re-ranging flag is ON by re-ranging determination processing (6-3). If the re-ranging flag is ON, the process proceeds to the process of starting the second distance measurement (6-4). If not, the distance value / area by the first distance measurement is selected (6-9). .

Next, the second distance measurement is started (6-4). The second distance measurement is performed according to the above AF distance measurement. The charge accumulation mode at this time is the automatic integration mode if the strobe auxiliary light flag is ON, and the forced accumulation mode is set otherwise. The charge accumulation time in the forced accumulation mode is a forced charge accumulation time obtained in a re-ranging determination process (FIG. 13) described later.
Next, second distance determination is performed on the calculation result of the second distance measurement (9-5). Here, in the second distance measurement, the reliability of the distance measurement value of the selected area is evaluated. If this evaluation result is valid (OK), the process proceeds to the next process. The first distance value / area is selected (6-9).

  Next, in the second distance measurement, it is determined whether or not the reliability of the distance measurement value of the area selected in the first distance measurement is high. If the reliability of the distance measurement value of the first distance measurement is low (NG), this second distance value / area is selected, and this is used as the final output. A comparison is made, and the distance measurement value and the area whose distance measurement value is closer are selected. That is, if the second distance value is near, the second distance value / area is selected (6-8). Otherwise, the distance value / area in the first distance is selected (6). -9). Finally, the selected distance value / area is output as the final distance value / area (6-10). The above is the description regarding the re-ranging calculation of FIG.

  Next, FIG. 13 is a flowchart of a series of flows for the re-ranging determination process during the re-ranging calculation described above. First, reliability determination (NG determination) is performed on the distance measurement result (7-1). Here, it is first determined whether or not the distance measurement value of the selected area is closer to the distance measurement value of the other area. If it is not the near side, if the difference between the distance measurement value and the distance measurement value of the near area exceeds a certain range, it is judged that re-distance measurement is necessary, and the process proceeds to the next. If so, it is determined that re-ranging is not necessary. In addition, although the distance measurement value of the selected area is a distance measurement value closer to the other area, the selected area is a distance measurement value trusted in the distance measurement determination process in the AF distance measurement flow described above. If it is low (NG), it is determined that re-ranging is necessary and the process proceeds to the next step. Otherwise, it is determined that re-ranging is not necessary.

  Next, when it is determined that re-ranging is necessary, it is determined whether the environment of the subject is low brightness or backlight (7-3). If the environment of the subject is low brightness or backlight, it is determined that the strobe auxiliary light is necessary, and the process proceeds to the next. Otherwise, the process proceeds to the charge accumulation time setting process (7-6). Here, whether the environment of the subject is low-intensity or backlight is determined by the size of sensor data from each area of the distance measuring unit (5), or by using an image sensor of a digital camera. This is done by using the photometric result obtained when calculating the appropriate exposure.

  Next, in the charge accumulation time setting process (7-6), if the distance measurement value of the selected area is not closer to the distance measurement value of the other area, the distance measurement value on the near side is obtained at this time. The area is set as an area for setting the charge accumulation time, and an optimum charge accumulation time is set for the light receiving elements in the area. If the distance measurement value of the selected area is a distance measurement value closer to the other area but the distance measurement value is not valid (NG), the selected area at this time is used as an area for setting the charge accumulation time. The optimum charge accumulation time is set for the light receiving elements in this area.

  This charge accumulation time setting function searches the light receiving element data in the area where the charge accumulation time is set in the first distance finding the minimum value, and finds the minimum value and the maximum in all the light receiving elements. A ratio with the value is obtained, and this is multiplied by the first charge accumulation time, and this is set as the forced charge accumulation time. Here, if there are multiple local minimum values, the largest value is selected, the ratio of that value to the maximum value in all the light receiving elements is obtained, and this is multiplied by the charge accumulation time at the first time. This is set as the forced charge accumulation time.

  Next, when it is determined in (7-3) that the subject environment requires strobe auxiliary light, the charge level of the strobe auxiliary light is a predetermined level (a level at which the auxiliary light can be emitted for a predetermined emission time). ) Is determined (7-4), if it is above a predetermined level, the strobe auxiliary light flag is turned ON (7-5), otherwise it is determined that the strobe auxiliary light cannot be emitted, and the charge The process proceeds to an accumulation time setting process (7-6). In this embodiment, the process proceeds to the charge accumulation time setting process. However, charging may be performed until the strobe charge level is equal to or higher than a predetermined level, and then the strobe auxiliary light flag may be turned ON. The above is the description of the re-ranging determination process in FIG.

  Next, processing in the normal mode in an actual camera will be described. As shown in the flowchart of FIG. 14, in the normal mode, external AF distance measurement (8-2, 8-3) without assisting is performed. See FIG. 11 for external AF distance measurement. Next, re-ranging determination (8-5, see FIG. 12 for details) is performed. If it is determined that re-ranging is not necessary, the focus extension amount is calculated from the distance value which is the external AF distance measurement result (8- 5) The focus is driven and controlled to the calculated feeding position (8-6). If it is determined in the re-ranging determination in 8-5 that re-ranging is necessary, it is next determined whether auxiliary light is necessary (8-7). If it is determined that the auxiliary light is unnecessary, the distance measurement is performed again without the auxiliary light.

  The setting of the charge accumulation time of the external AF at this time is a time obtained in the re-ranging determination process (FIGS. 12 and 13) based on the first distance measurement result. In the determination of reliability of the distance measurement result, if it is determined to be OK, the focus feeding beam is calculated from the distance value obtained by re-ranging, and drive control is performed (8-5, 8-6). When it is determined as NG in the reliability determination, the normal focus position corresponding to each zoom position is calculated (8-10), and the focus lens is driven to the normal focus position (8-11). If it is determined in the auxiliary light determination that auxiliary light is necessary, the camera waits for the release to be fully pressed without performing re-distance measurement, calculation of the feeding amount, and feeding driving (8-12).

  When full release is detected, auxiliary light determination is performed (8-13). If it is determined that auxiliary light is not required when half-pressed, the recording AE setting, imaging, image processing, and card recording processing A series of recording processes are performed (8-20 to 8-23). In the auxiliary light determination, if it is determined that auxiliary light is necessary when half-pressed, external AF distance measurement is performed with auxiliary light (8-14). In the external AF distance measurement at this time, the distance measurement operation is performed in a synchronized state so that the strobe emits a minute light during integration.

  In the reliability determination of the re-ranging result (8-15), when it is determined to be OK, the focus extension amount is calculated from the distance value by the re-ranging with auxiliary light, and drive control is performed (8-16, 8). -17). When it is determined as NG in the reliability determination, the normal focus position corresponding to each zoom position is calculated (8-18), and the focus lens is driven to the normal focus position (8-19). After the completion of feeding, recording AE setting, imaging, image processing, card recording, and a series of recording processes are performed (8-20 to 8-23).

  Next, processing in the self mode in an actual camera will be described. As shown in the flowchart of FIG. 15, in the shooting in the self mode, when half-pressing of the release is detected (9-1), external AF distance measurement (9-2, 9-3 without photometry and auxiliary light) is performed. The external AF distance measurement is performed as shown in FIG. Next, re-ranging determination (9-5, see FIG. 12 for details) is performed. If it is determined that re-ranging is not necessary, the focus extension amount is calculated from the distance value which is the external AF distance measurement result (9- 5) The focus is driven and controlled to the calculated feeding position (9-6). If it is determined in the re-ranging determination in 8-5 that re-ranging is necessary, it is next determined whether auxiliary light is necessary (9-7). If it is determined that the auxiliary light is unnecessary, the distance measurement is performed again without the auxiliary light.

  The setting of the charge accumulation time of the external AF at this time is the time obtained in the re-ranging determination process (FIGS. 12 and 13) based on the first distance measurement result. In the determination of the reliability of the distance measurement result, if it is determined to be OK, the focus extension amount is calculated from the distance value obtained by re-ranging, and drive control is performed (9-5, 9-6). When it is determined as NG in the reliability determination, the normal focus position corresponding to each zoom position is calculated (9-10), and the focus lens is driven to the normal focus position (9-11). If it is determined in the auxiliary light determination that auxiliary light is necessary, the camera waits for the release to be fully pressed without performing re-distance measurement, calculation of the amount of feeding, and driving of feeding (9-12).

  When the release button is fully pressed, the self LED blinks (9-13). After lighting for 8 seconds and flashing for 2 seconds, the auxiliary light determination is performed (9-14). If it is determined that auxiliary light is not required when half-pressed, the recording AE setting, imaging, image processing, A recording process and a series of recording processes are performed (9-21 to 9-24). If it is determined in the auxiliary light determination that auxiliary light is necessary when half-pressed, external AF distance measurement is performed with auxiliary light (9-15). In the external AF distance measurement at this time, the distance measurement operation is performed in a synchronized state so that the strobe emits a minute light during integration.

  In the reliability determination of the re-ranging result (9-16), when it is determined to be OK, the focus extension amount is calculated from the distance value by the re-ranging with auxiliary light, and the drive control is performed (9-17, 9). -18). When it is determined as NG in the reliability determination, the normal focus position corresponding to each zoom position is calculated (9-19), and the focus lens is driven to the normal focus position (9-20). After the feeding is completed, AE setting for recording, imaging, image processing, recording on the card and a series of recording processes are performed (9-21 to 9-24).

In this embodiment, the strobe light is used as the auxiliary light, but there is no problem with the LED and the lamp. In this embodiment, the passive external AF is taken up as the AF method. However, the active external method, the TTL phase difference detection method, and the hill-climbing CCD-AF method are also possible.

  The present invention can be used for a mobile phone with a built-in camera in addition to a silver salt camera and a digital camera.

It is a top view at the time of applying this invention to a digital camera. It is a front view of the digital camera of FIG. FIG. 2 is a rear view of the digital camera of FIG. 1. It is a block diagram of the digital camera of FIG. It is a figure which shows the structure of an external AF unit. It is a figure which shows the principle of operation of the ranging element used by this invention. It is a figure explaining the light reception area of a light reception sensor. It is a figure explaining the light reception data received in each light reception area. It is a figure explaining the contrast regulation value of received light data. It is a figure explaining the left-right image difference of received light data. It is a flowchart which shows the distance measurement process content of AF unit. It is a flowchart which shows the re-ranging calculation processing content of AF unit. It is a flowchart which shows the re-ranging determination processing content in the re-ranging calculation of FIG. It is a flowchart which shows the imaging process at the time of normal mode. It is a flowchart which shows the imaging process at the time of self mode.

Explanation of symbols

1 Sub LCD (Liquid Crystal Display)
2 SD card / battery cover 3 Flash unit 4 Optical viewfinder 5 Ranging unit (external AF unit)
6 Remote control light receiving unit 7 Lens barrel unit 7-1 Zoom optical system 7-1a Zoom lens 7-1b Zoom drive motor 7-2 Focus optical system 7-2a Focus lens 7-2b Focus drive motor 7-3 Aperture unit 7-3a Aperture 7-3b Aperture motor 7-4 Mechanical shutter unit 7-4a Mechanical shutter 7-4b Mechanical shutter motor 7-5 Motor driver 8 AF LED
9 Strobe LED
DESCRIPTION OF SYMBOLS 10 LCD monitor 11 Light reception sensor 11-1 Right light reception sensor 11-2 Left light reception sensor 12 Distance element control unit 13 Lens 13-1 Right lens 13-2 Left lens 14 Aperture 101 CCD
102 F / E (front end) -IC
102-1 CDS
102-2 ADC
102-3 A / D
102-4 TG
103 SDRAM
104 Digital still camera processor 104-1 CCD1 control block 104-2 CCD2 control block 104-3 CPU block 104-4 Local SRAM
104-5 USB block 104-6 Serial block 104-7 JPEGCODEC block 104-8 Resize block 104-9 TV signal display block 104-10 Memory card block 107 RAM
108 ROM
109 Sub-CPU
111 LCD Driver 113 Buzzer 115 Audio Recording Unit 115-1 Audio Recording Circuit 115-2 Microphone AMP
115-3 microphone 116 audio reproduction unit 116-1 audio reproduction circuit 116-2 audio AMP
116-3 Speaker 118 Video AMP
119 Video jack 120 Internal memory 121 Memory card throttle 122 USB connector 123-1 Serial driver circuit 123-2 RS-232C connector 124 Memory card SW1 Release shutter SW2 Mode dial SW3 Zoom switch (wide)
SW4 Zoom switch (far / near)
SW5 Self-timer / Delete switch SW6 Menu switch SW7 Up / Strobe switch SW8 Right switch SW9 Display switch SW10 Down / Macro switch SW11 Left / Image confirmation switch SW12 OK switch SW13 Power switch

Claims (9)

A shooting operation member having a two-step operation position of half-press and full-press;
Ranging means based on triangulation or phase difference detection method for measuring the distance to the subject,
Reliability determination means for determining reliability based on a distance measurement result of the distance measurement means;
A focus adjustment position calculating means for calculating a focus adjustment position based on a distance measurement result of the distance measuring means;
Focus adjustment control means for performing focus adjustment based on the calculation result of the focus adjustment position calculation means;
Auxiliary light irradiation means for irradiating the subject with auxiliary light;
Exposure control means for performing exposure;
In complement Johikari function imaging apparatus having a
An auxiliary light determining unit that determines whether auxiliary light is necessary, and when the photographing operation member is in a half-pressed state, the auxiliary light determining unit performs the determination and determines that auxiliary light is necessary; Auxiliary light is emitted by the auxiliary light irradiating means when the photographing operation member is fully pressed without performing the auxiliary light irradiation by the light irradiating means and the focus adjustment by the focus adjustment control means, performed by Rihaka distance, measuring said focusing position calculation means on the basis of the distance results to calculate the focusing position, after the focus adjustment control means based on said focus adjusting position has focus adjustment control, said exposure control An imaging apparatus with an auxiliary light function, wherein the means performs exposure. In the imaging device with an auxiliary light function according to claim 1,
An imaging apparatus with an auxiliary light function, wherein a strobe is used as the auxiliary light irradiation means. In the imaging device with an auxiliary light function according to claim 1,
An imaging apparatus with an auxiliary light function, wherein an LED is used as the auxiliary light irradiation means. In the imaging device with an auxiliary light function according to claim 1,
An imaging device with an auxiliary light function, wherein a lamp is used as the auxiliary light irradiation means. In the imaging device with an auxiliary light function according to any one of claims 1 to 4,
The auxiliary light determination unit determines that the auxiliary light is necessary when the reliability determination unit determines that the reliability is low. In the imaging device with an auxiliary light function according to any one of claims 1 to 5,
The auxiliary light determining unit according to claim 1, wherein the auxiliary light determining means determines that auxiliary light is necessary when the subject environment has low luminance. In the imaging device with an auxiliary light function according to any one of claims 1 to 6,
The auxiliary light determination unit according to claim 1, wherein the auxiliary light determination unit determines that auxiliary light is necessary when the subject environment is in a backlight state. In the imaging device with an auxiliary light function according to any one of claims 1 to 7,
When it is determined that the reliability is low by the determination of the reliability determination unit based on the distance measurement result measured by the distance measurement unit when the photographing operation member is fully pressed, the focus adjustment control unit Is an imaging device with an auxiliary light function, wherein focus adjustment control is performed with the focus adjustment position as a fixed position. In the imaging device with an auxiliary light function according to claim 8,
The imaging apparatus with an auxiliary light function, wherein the fixed position is an ordinary focal length position.

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