JP2012163923A - Range finder, method, and program, and imaging apparatus, method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a range finder and an imaging apparatus equipped with the range finder, in which, when an unnecessary state of AF processing is detected, a specific power supply is stopped among a plurality of electric power sources used for operation of the range finder to reduce power consumption.SOLUTION: A range finder comprises: first and second range-finding elements outputting first and second ranging signals respectively according to a subject image image-formed by first and second ranging lenses image-forming incident light from a subject; an image conversion part capable of communicating with a main controller specifying a distance to the subject based on the first and second ranging signals and converting the first and second ranging signals for interface of the main controller; and a power source control part for controlling electric power supplied to the image conversion part. The power source control part stops the power supply to the image conversion part when shifting from a normal mode to a power-saving mode.

Description

  The present invention is a distance measuring device that specifies a distance to a subject using two images obtained via two image sensors for distance measurement, and an imaging device including the same, in which AF processing is unnecessary The present invention relates to a distance measuring device that reduces power consumption by stopping the supply of a specific power source among a plurality of power sources used for the operation of the distance measuring device, and an imaging device equipped with the same.

  A plurality of methods are known for an automatic focusing function (AF function) mounted on an imaging apparatus typified by a compact digital camera. For example, there are a hill-climbing AF method and a phase difference detection AF method. The hill-climbing AF method acquires an image at a predetermined timing while moving the lens constituting the imaging optical system, and moves the lens to the lens position from which the image with the maximum contrast value is acquired. This is a method of focusing on the subject. That is, in the hill-climbing AF method, it is necessary to actually drive the lens of the imaging optical system within a predetermined driving range. Therefore, when the long focus lens is used, the range in which the lens is driven becomes large, and there is a problem that the processing time until the in-focus position is specified becomes long.

  The phase difference detection AF method can perform the focusing process faster than the hill-climbing AF method. An imaging apparatus using the phase difference detection AF method includes an optical system (ranging optical system) that is different from the imaging optical system that acquires a captured image, and the ranging optical system includes two imaging elements. In the phase difference detection AF method, two images are acquired via each image sensor, a phase difference (parallax) between the images is calculated, and a distance to the subject is calculated based on the phase difference. The phase difference detection AF method does not need to drive the lens and can be calculated based on the subject image, so that the in-focus position can be specified more quickly than the hill-climbing AF method. However, the two images are output from different image sensors. If the acquisition timing and image quality of each image do not match, accurate parallax cannot be calculated. Therefore, in the phase difference detection AF method, the image output timing of each image sensor is synchronized, It is important that the device specifications meet. Such a high-performance image sensor is expensive. In addition, it is necessary to mount a distance measuring optical system different from the imaging optical system, and it is necessary to increase the assembly accuracy of the distance measuring optical system, which increases the number of components and increases the manufacturing cost. .

  As a method for solving the problems of the hill-climbing AF method and the phase difference detection AF method, a hybrid AF method in which both methods are combined is known (see, for example, Patent Document 1).

  In the hybrid AF method, first, the distance to the subject is roughly calculated by the phase difference detection AF method, and after moving the lens of the imaging optical system to a predetermined lens position based on the calculated distance, the vicinity of the moved lens position This is a method of focusing by climbing the hill within the predetermined range and executing the AF method. According to the hybrid method, the calculation accuracy of the distance by the phase difference detection AF method may not be so high, and in the hill-climbing AF method, the range for driving the lens can be narrowed down, so that the time until focusing is reduced. It can be shortened.

  Japanese Patent Application Laid-Open No. 2004-228561 describes an apparatus that is equipped with a hybrid AF method and changes the AF area used for focus detection in the hill-climbing AF method in accordance with the multipoint ranging area obtained by an AF unit equipped with a ranging optical system. Has been. Patent Document 2 describes an apparatus for changing an AF area used in a hill-climbing AF method according to the distance to a subject. In any apparatus described in any of the documents, the AF area to be focused by the hill-climbing AF method needs to be an area that matches the distance measurement angle of the distance measurement optical system that is a fixed focus.

  In recent years, while higher speed and higher accuracy are required for the AF function, there are increasing demands for reducing the manufacturing cost of the distance measuring device itself and reducing power consumption. In order to cope with higher speed and higher accuracy with the conventional distance measuring device, in the phase difference detection AF method, synchronization of output timings of two images using an image sensor having an advanced timing adjustment function is more accurately synchronized. Or, it is necessary to devise such as developing a dedicated sensor that incorporates an image sensor that outputs two images in a custom IC, or using a combination thereof.

  However, an imaging device having a timing adjustment function or a custom IC has a high development cost and manufacturing cost, which is contrary to a reduction in manufacturing cost of the distance measuring device itself. If attention is paid only to the reduction of the manufacturing cost or the like, a general-purpose and low-priced image sensor may be used. However, a new design change occurs to make the general-purpose image sensor compatible with a conventional ranging device system.

  Generally, a system LSI in which a CPU and image processing are integrated is used as an LSI that performs processing related to overall control of the imaging apparatus. In many cases, system LSIs do not support a significant increase in interface. Therefore, the correspondence on the system LSI side required when two general-purpose and low-priced image sensors are incorporated in a conventional distance measuring device must be based on a change in the specifications of the system LSI. Changing the specifications of the system LSI takes time and cost, which hinders early commercialization. Therefore, a new problem arises when using a general-purpose and low-cost image sensor.

  Therefore, when a general-purpose and low-priced image sensor is incorporated in the distance measuring device, the distance measuring device (so that the image sensor can be added even when the corresponding interface is not on the system LSI side. A method of using a conversion circuit (conversion IC) between an image pickup element) and an image pickup apparatus (system LSI) is known. However, if the conversion circuit is used, the power consumption of the entire distance measuring device system increases, the battery consumption of the distance measuring device and the image pickup apparatus equipped with the same increases, and long-term continuous operation becomes difficult. The problem arises.

  In order to solve this problem, when the distance measuring device does not need to be operated in real time, a method of switching to the energy saving mode by turning off the operation power of the circuits and the image sensor constituting the image capturing device can be considered. However, since the conversion circuit is configured by using a plurality of power supplies such as an FPGA, the power control related to the transition to and the return to the energy saving mode becomes complicated, and the time required for the control increases. In addition to the increase in the number of components for power supply control and the accompanying increase in manufacturing cost, a new problem of pressing the circuit board layout arises.

  In order to reduce battery consumption related to the distance measuring device, when performing focusing operation repeatedly in the continuous AF mode, the time interval of restart and the reference change amount of the focus evaluation value when the restart is performed, There is known a camera that realizes an operation that is optimal for the shooting condition by setting according to the shooting condition and the like, and suppresses wasteful consumption of the battery (see, for example, Patent Document 2).

  The camera disclosed in Patent Document 2 can reduce wasteful battery consumption by suppressing unnecessary contrast AF processing by varying the AF evaluation value in the contrast AF method according to the shooting conditions. However, in a distance measuring device that performs distance measurement by the phase difference detection AF method using two general-purpose image sensors without changing the specifications of the system LSI used in the conventional distance measuring device, the cost reduction and the battery Nothing is known that can solve the problem of reducing consumption.

  The present invention has been made in view of the above-described problems, and is a distance measuring device that measures a distance using images obtained via two distance measuring image sensors, and can be manufactured at a low cost and is simple. It is an object of the present invention to provide a distance measuring device having a configuration capable of realizing an energy saving mode by control, and an imaging device including the device.

  The present invention relates to a distance measuring apparatus that can shift between a normal mode and a power saving mode, and includes a first distance measuring lens and a second distance measuring lens that form an incident light from a subject, and a first distance measuring device. A first distance measuring element that outputs a first distance measuring signal corresponding to the subject image formed by the distance lens, and a second distance measuring signal that corresponds to the subject image formed by the second distance measuring lens are output. A second distance measuring element, and a main control device that specifies a distance to the subject based on the first distance signal and the second distance signal, can be notified, the first distance signal and the second distance measurement An image conversion unit that converts a signal for an interface of the main control device, and a power supply control unit that controls power supplied to the image conversion unit. The power supply control unit changes from a normal mode to a power saving mode. The main feature is that the power supply to the image conversion unit is stopped when the process is shifted to step (b).

  The present invention also relates to the distance measuring apparatus described above, comprising a plurality of power sources for driving the image conversion unit, and the power source control unit stops power supply from some of the plurality of power sources. , That feature.

  The present invention also relates to the distance measuring device described above, comprising a clock supply unit that supplies operation clocks of the first distance measuring element and the second distance measuring element via the image conversion unit, and the power supply control unit includes: When shifting from the normal mode to the power saving mode, the power supply to the clock supply unit is stopped, and the clock supply unit is stopped from supplying the operation clock.

  Further, the present invention relates to the distance measuring apparatus described above, and includes a clock supply unit that supplies operation clocks of the first distance measuring element and the second distance measuring element via the image conversion unit, and the clock supply unit includes: When shifting from the normal mode to the power saving mode, the operation clock supply to either one of the first distance measuring element and the second distance measuring element is stopped.

  The present invention also relates to the distance measuring device described above, wherein the main control device is connected to the display, and the operation clock supply of the first distance measuring element and the second distance measuring element is not stopped. An image corresponding to a distance measurement signal output from the distance element is displayed on a display.

  Further, the present invention relates to the distance measuring device described above, wherein the output timing of the distance measuring signals output per unit time by the first distance measuring element and the second distance measuring element can be changed. To do.

  In addition, the present invention is a distance measuring device capable of transitioning between a normal mode and a power saving mode, in accordance with a distance measuring lens that forms incident light from a subject and a subject image that is formed by the distance measuring lens. A distance measuring element that outputs a distance measurement signal, an image that can be notified to a main control device that specifies the distance to the subject based on the distance measurement signal, and converts the distance measurement signal for use as an interface of the main control device And a power supply control unit that controls power supplied to the image conversion unit. The power supply control unit is supplied to the image conversion unit when shifting from the normal mode to the power saving mode. A part of the electric power is stopped.

  The present invention also relates to the distance measuring apparatus described above, comprising a plurality of power sources for driving the image conversion unit, and the power source control unit stops power supply from some of the plurality of power sources. It is characterized by that.

  In addition, the present invention relates to the distance measuring device described above, and includes a clock supply unit that supplies an operation clock of the distance measuring element via the image conversion unit, and the power control unit switches from the normal mode to the power saving mode. When shifting, the power supply to the clock supply unit is stopped, and the clock supply unit is stopped from supplying the operation clock.

  According to another aspect of the present invention, there is provided an imaging optical system including an imaging lens that forms incident light from a subject, an imaging element that outputs an imaging signal corresponding to the subject image formed by the imaging lens, A distance measuring optical system including a distance measuring lens that forms an incident light, a distance measuring element that outputs a distance measuring signal according to a subject image formed by the distance measuring lens, and a distance measuring signal The present invention relates to an imaging apparatus comprising: a main control unit that specifies a distance to a subject and calculates a movement amount of the imaging lens; and a focusing unit that moves the imaging lens in the optical axis direction based on the calculated movement amount The distance measuring optical system is any one of the distance measuring devices described above.

  The present invention also relates to a distance measuring method, which corresponds to a first distance measuring lens and a second distance measuring lens that form incident light from a subject, and a subject image formed by the first distance measuring lens. A first ranging element that outputs a first ranging signal, and a second ranging element that outputs a second ranging signal corresponding to the subject image formed by the second ranging lens, The main control device that identifies the distance to the subject based on the first distance measurement signal and the second distance measurement signal can be notified, and the first distance measurement signal and the second distance measurement signal are converted for the interface of the main control device. A normal mode and a power-saving mode, including an image conversion unit that performs power conversion, a power control unit that controls power supplied to the image conversion unit, and a plurality of power sources that drive the image conversion unit. This can be executed in the distance device, and when the mode is changed from the normal mode to the power saving mode, the power Control unit, to stop some of the power supplied to the image converting unit, and wherein the.

  The present invention also relates to the distance measuring method, wherein the distance measuring device includes a clock supply unit that supplies an operation clock to the first distance measuring element and the second distance measuring element via the image conversion unit. The power supply control unit has a step of stopping the power supply to the clock supply unit and the clock supply unit stops the supply of the operation clock when shifting from the normal mode to the power saving mode. It is characterized by becoming.

  The present invention also relates to a distance measuring program, which corresponds to a first distance measuring lens and a second distance measuring lens that form an incident light from a subject, and a subject image formed by the first distance measuring lens. A first ranging element that outputs a first ranging signal, and a second ranging element that outputs a second ranging signal corresponding to the subject image formed by the second ranging lens. Is made to function as any one of the distance measuring devices described above.

  The present invention also relates to an imaging program, comprising: an imaging lens that forms incident light from a subject; and an imaging element that outputs an imaging signal corresponding to the subject image formed by the imaging lens. Ranging optical system comprising: an imaging optical system; a distance measuring lens that forms incident light from a subject; and a distance measuring element that outputs a distance measuring signal corresponding to the subject image formed by the distance measuring lens And a main control unit that specifies the distance to the subject based on the distance measurement signal and calculates the movement amount of the imaging lens, and a focusing unit that moves the imaging lens in the optical axis direction based on the calculated movement amount And an image pickup apparatus having the above functions as the image pickup apparatus.

  According to the present invention, when an AF operation is not necessary, such as when shooting processing is not being performed, the two ranging image sensors used in the phase difference detection AF method are shifted to the energy saving mode, and the main sensor is switched from the ranging image sensor. By stopping the supply of the operation clock to the image input conversion interface circuit to the LSI and further stopping the supply of the specific operation power from among the plurality of operation power supplies, “start-up and shutdown” based on the sequence of each power supply ”Is not necessary, and the startup speed is increased by reducing the control sequence, the circuit configuration is simplified, the control is simplified, and the power consumption can be reduced.

1 is an external perspective view showing an example of an imaging apparatus according to the present invention. It is a functional block diagram which shows the example of the said imaging device. It is a schematic diagram explaining the principle of a phase difference detection AF system. 5 is a flowchart illustrating an example of AF processing executed by the imaging apparatus according to the present invention. It is a block diagram which shows the example of the ranging apparatus which concerns on this invention. It is a block diagram which shows the example of an internal structure of the said distance measuring device. It is a flowchart which shows the example of the energy-saving mode transfer process which the said ranging device performs. It is a flowchart which shows the example of the return process to the normal mode which the said ranging device performs. It is a timing chart which shows the example at the time of the energy-saving mode transition which the said ranging device performs. It is a timing chart which shows the example at the time of the return to the normal mode which the said ranging device performs. It is a block diagram which shows another example of the ranging apparatus which concerns on this invention. It is a block diagram which shows another example of the internal structure of the said ranging apparatus.

  Hereinafter, embodiments of a distance measuring device, method, and program, and an imaging device, method, and program according to the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing an example of an imaging apparatus according to the present invention. In FIG. 1, an imaging optical system 20 that acquires a subject image via an imaging lens including a focus lens and a distance measurement that acquires a subject image via a distance measuring lens 111 and a distance measuring lens 112 are provided in front of the imaging device 1. A distance measuring device 100 having an optical system is provided. The imaging optical system 20 and the distance measuring device 100 are arranged at positions separated from each other on the imaging device 1. As shown in FIG. 1, a release button SW <b> 1 that is a shutter switch and a mode dial SW <b> 2 for selecting a shooting mode are disposed on the upper end surface of the imaging apparatus 1. The release button SW1 has two switches arranged therein, and has a configuration in which a first release signal is generated when the release button SW1 is half-pressed, and a second release signal is generated when the release button SW1 is fully pressed. In response to these release signals, the imaging apparatus 1 performs AF processing.

  FIG. 2 is a functional block diagram illustrating an example of an imaging apparatus according to the present invention. In FIG. 1, an imaging apparatus 1 includes a main control unit 10, an optical system 20, an imaging element 30, an A / D conversion circuit 40, a liquid crystal display device (LCD) 50, an optical system driving circuit 60, and a storage circuit. 70, an external I / F 80, and a distance measuring device 100.

  The main control unit 10 includes a CPU and its peripheral circuits, controls related to various operations in the imaging apparatus 1 (mechanical drive control and electrical drive control), various image processing, liquid crystal display control, memory control, Various controls such as information communication control via an external interface are executed.

  The optical system 20 forms an object image on the image sensor 30. The image sensor 30 converts an image formed into an electric signal. The A / D conversion circuit 40 performs processing for converting a subject image signal composed of an electrical signal (analog signal) output from the image sensor 30 into a digital signal.

  The main control unit 10 performs predetermined image processing on the digital subject image signal converted by the A / D conversion circuit 40 and displays it on the LCD 50 as necessary. The optical system driving circuit 60 is controlled by the main control unit 10 and drives the optical system 20 along the optical axis direction to perform focusing adjustment, that is, focus adjustment.

  The distance measuring device 100 is a device that measures the distance to the subject by the phase difference detection AF method.

  The imaging device 1 also has a function of performing a contrast analysis or the like based on subject image data input from the imaging element 30 and detecting a focused state. The storage circuit 70 includes a RAM and a ROM, and includes image data input from the image sensor 30 and processed by the main control unit 10, data related to processing including intermediate data related to operation and control processing of the main control unit 10, and the like. Furthermore, image data that has been captured and captured is stored.

  The main control unit 10 also includes a memory controller for an external storage device, and can write to and read from the external memory via the external I / F 80. When photographing, the main control unit 10 causes the liquid crystal display device 50 to display a subject image acquired via the optical system 20, the image sensor 30, and the A / D conversion circuit 40. Although not clearly shown in the figure, the operation control of the image sensor 30, the A / D conversion circuit 40, and the LCD 50 is performed by the main control unit 10.

  In addition, the main control unit 10 controls the optical system driving circuit 60 based on the distance to the subject calculated by the distance measuring device 100 using the phase difference AF method, so that the imaging lens constituting the optical system 20 is placed at a predetermined position. Then, the imaging lens is moved within a predetermined movement range to acquire and analyze contrast data, thereby realizing a hybrid autofocus function.

  Further, the main control unit 10 performs AF processing at a predetermined cycle. When the release button SW1 is pressed halfway and a first release signal is generated, a new AF process is started. The result of the AF process is that the first release signal is being generated (the release button SW1 is pressed halfway). Is maintained). If the release button SW1 is released in this state, the main control unit 10 returns control to the AF processing with a predetermined period. When the release button SW1 is further pressed from the half-pressed state and is fully pressed to generate the second release signal, the main control unit 10 stores the image data in the storage circuit 70, and then displays an image confirmation screen on the LCD 50, etc. Display is performed, and write transfer is performed to the external memory via the external I / F 80.

  Next, the operation of the distance measuring apparatus according to the present invention will be described. FIG. 3 is a schematic diagram for explaining the principle (ranging principle) for calculating the distance to the subject in the phase difference detection AF method. In FIG. 3, the distance measuring device 100 included in the imaging device 1 illustrates only a first distance measuring lens 111, a second distance measuring lens 112, a first distance measuring element 121, and a second distance measuring element 122. The first distance measuring element 121 and the second distance measuring element 122 are imaging elements such as a CCD, and are two-dimensional corresponding to the image of the subject X formed by the first distance measuring lens 111 and the second distance measuring lens 112. It is an element that outputs the image. FIG. 3 illustrates a state where the imaging device 1 is viewed from the upper surface side.

In FIG. 3, the distance between the first distance measuring lens 111 and the second distance measuring lens 112 is the base line length B, the focal length of the first distance measuring lens 111 is fL, and the focal length of the second distance measuring lens 112 is fR. . In FIG. 3, since the focal lengths fL and fR are fL = fR, the focal lengths of the first distance measuring lens 111 and the second distance measuring lens 112 will be described as “f”. The image formed on the first distance measuring element 121 via the first distance measuring lens 111 is at a position dL with respect to the base line length B, and is connected to the second distance measuring element 122 via the second distance measuring lens 112. When the imaged image is at the position of dR with reference to the base line length B, the distance to the subject X can be calculated by Equation 1 using the base line length B and the imaging positions dL and dR.
(Formula 1)
L = {(B + dL + dR) × f} / (dL + dR)

  Thus, by measuring dL and dR with reference to the baseline length B, the distance L to the subject X can be calculated. The conversion to the amount of extension of the imaging lens according to the distance L may be obtained by storing the adjustment system number calculated in advance in the storage circuit 70 of the imaging apparatus 1 and referring to this. The base line length B is required to be 6 mm or more depending on the size of the distance measuring device and the restrictions and specifications of the distance measuring element.

  Next, the overall flow of the AF process executed in the imaging apparatus 1 according to the present embodiment will be described with reference to the flowchart of FIG. The AF processing according to the present embodiment performs high-precision in-focus position detection using the hill-climbing AF method after performing a certain distance measurement using the phase difference detection AF method. In FIG. 4, each processing step is expressed as S10, S20, S30.

  When the release button SW1 is half-pressed to generate the first release signal, the AF process starts, and exposure control is first performed (S10). Next, focus processing (AF processing) by the phase difference detection AF method is performed (S20). Next, a process for determining the result of the AF process (S20) is performed (S30). If it is determined that focusing has failed (No in S30), a failure condition determination process (S70) is performed. In the failure condition determination process (S70), when it is determined that the AF process (S20) is performed again (No in S70), the process returns to S20. If it is determined in the failure condition determination process (S70) that the process is to be terminated (Yes in S70), an error is displayed on the LCD 50 (S90), and the process is terminated. Here, the error display refers to, for example, displaying a result of failure by showing a red frame region or the like.

  In the determination process (S30), if it is determined that focusing is successful (Yes in S30), AF using the hill-climbing AF method at the peripheral position of the lens position according to the distance calculated by the phase difference detection AF method Processing is performed (S40). Next, a process of determining the result of the AF process (S40) by the hill-climbing AF method is performed (S50). In this determination process, if it is determined in the AF process (S40) that focusing has failed (No in S50), a failure condition determination process (S80) is performed. In the failure condition determination process (S80), when it is determined that the AF process (S40) is performed again (No in S80), the process returns to S40. In the failure condition determination process (S80), when it is determined that the process is to be ended (Yes in S80), an error is displayed on the LCD 50 (S90), and the process is ended. Here, the error display refers to, for example, displaying a result of failure by showing a red frame region or the like.

In the determination process (S50), if it is determined that focusing is successful (Yes in S50)
A success message is displayed on the LCD 50 (S60). Here, “success display” refers to displaying a result of success on the LCD 50 by displaying a green frame region or the like.

  Note that the display on the LCD 50 in the error display process (S90) may use a color different from the color exemplified above, and further, blinking display instead of the colored frame display and the display mode of the area mark are changed. For example, another symbol indicating inappropriate AF may be displayed.

  Next, an embodiment of a distance measuring device according to the present invention will be described with reference to the drawings. FIG. 5 is a block diagram of the distance measuring apparatus according to the present embodiment. In FIG. 5, a distance measuring device 100 includes a first distance measuring lens 111 and a second distance measuring lens 112 that form incident light from a subject to be imaged, and a photoelectric that accumulates electric charges corresponding to the formed optical image. The first distance measuring element 121 and the second distance measuring element 122 in which conversion elements are spread on a matrix, and drive control of each image sensor, and output image signals output by each image sensor to the main control unit 10 An image conversion unit 130 that performs a conversion process to perform the operation, a CLK supply unit 131 that supplies operation reference clocks of the first distance measuring element 121 and the second distance measuring element via the image conversion unit 130, and the main control unit 10. And a power supply control unit 132 that controls power supply to the CLK supply unit 131 in accordance with an instruction from.

  Next, an example of the internal configuration of the image conversion unit 130 will be described with reference to FIG. The image conversion unit 130 supplies a clock to the first distance measuring element 121 and the second distance measuring element 122 based on the operation reference clock supplied from the CLK supply unit 131 according to an operation instruction from the main control unit 10. The first distance measuring element 121 and the second distance measuring element 122 output an image of the subject X (see FIG. 3) to the image conversion unit 130 in accordance with the supplied operation clock. Images output from the first distance measuring element 121 and the second distance measuring element 122 are distance measurement signals. The image conversion unit 130 receives the distance measurement signals output from the first distance measuring element 121 and the second distance measuring element 122 with a Video I / F optimized for each distance measuring element.

  Further, the image conversion unit 130 is a signal corresponding to the Video I / F of the main control unit 10 in order to transfer the distance measurement signals received from the first distance measuring element 121 and the second distance measuring element 122 to the main control unit 10. Process to convert to format. The converted ranging signal is output to the main control unit 10 and used for parallax calculation. As described above, each of the ranging signals output (obtained) from the first ranging element 121 and the second ranging element 122 is subjected to predetermined conversion processing by the image conversion unit 130, and the imaging apparatus 1. Is used for focusing processing by the phase difference detection AF method.

  The image conversion unit 130 requires a plurality of operating power sources. For example, a core power supply (1.2V), an I / O power supply 1 (1.8V), a PLL power supply (2.5V), and an I / O power supply 2 (3.1V). In FIG. 6, the power lines from the respective power supplies that supply power necessary for the operation of the distance measuring device 10 are not illustrated except for a part thereof. Power supply control from a PLL power supply (2.5 V) (hereinafter referred to as “specific power supply”), which is a specific operation power supply among the plurality of operation power supplies, operates according to an instruction from the main control unit 10. Controlled by the unit 132. By stopping the supply of power from the specific power supply and starting the supply, the image conversion unit 130 shifts from the normal mode to the energy saving mode or returns from the energy saving mode to the normal mode.

  In accordance with the control of the operation mode of the image conversion unit 130, the transition to the energy saving mode and the return to the normal mode of the first distance measuring element 121 and the second distance measuring element 122 are also controlled. Since the specific power supply is also an operation power supply for the CLK supply unit 131, the power supply from the specific power supply to the CLK supply unit 131 is stopped at a predetermined timing when the normal mode is shifted to the energy saving mode. When the power supply to the CLK supply unit 131 is stopped, the supply of the operation reference clock to the image conversion unit 130 is stopped, so that the output of ranging signals from the first image sensor 121 and the second image sensor 122 is stopped.

  The energy saving mode refers to a state in which the operation of the image conversion unit 130 is stopped by stopping the supply of power from the specific power source to the image conversion unit 130 and stopping the supply of power from the specific power source to the CLK supply unit 131. When the power supply from the specific power supply is stopped, the operation clock supply from the CLK supply unit 131 to the image conversion unit 130 is stopped. When the supply of the operation clock is stopped, the internal circuit of the image conversion unit 130 does not operate, so the power supply from other power sources (core power source, I / O power source 1, I / O power source 2) is not stopped. However, the current consumption in the image converter 130 is reduced to several milliamperes. Since the PLL generates a static current of about 20 milliamperes in the analog portion, the power saving effect can be maximized by stopping the supply of the specific power source that is a PLL power source. Thereby, the power consumption of the distance measuring device 100 can be reduced. Note that the power saving effect of the energy saving mode by stopping the power supply from the specific power source is approximately 50 milliwatts.

  Also, in the energy saving mode, by stopping only the supply of specific power and continuing the supply of other power supplies, it is possible to reduce the waiting time for starting up each power supply when returning from the energy saving mode to the normal mode. Thus, the recovery time can be shortened.

  In addition, there is another embodiment in the energy saving mode in the imaging apparatus 1 according to the present embodiment. For example, when shifting to the energy saving mode, power supply from the specific power source to the image conversion unit 130 is stopped, and power supply to the CLK supply unit 131 is continued. In this state, the supply of the operation clock to either the first distance measuring element 121 or the second distance measuring element 121 is stopped. As a result, out of the two distance measuring elements, either the first distance measuring element 121 or the second distance measuring element 121 stops outputting the distance measuring signal, but the other distance measuring signal is output. The Thereby, the power consumption for one distance measuring element can be reduced. The ranging signal output from one ranging element that continues to operate is an image signal related to the subject. Therefore, if this image signal is transferred to the main controller 10, it can be displayed on the LCD 50 of the imaging apparatus 1 as a through image.

  In this case, even if the operation of the image sensor 30 included in the distance measuring device 1 is stopped, the image capturing device 1 can display a through image. Since the image sensor 30 consumes more power than the distance measuring element, the operation of the image sensor 30 is stopped and only the first distance measuring element 121 or the second distance measuring element 122 is operated to display a through image. In addition, power consumption can be reduced.

  Further, the energy saving mode in the imaging apparatus 1 according to the present embodiment includes still another embodiment. For example, when the mode is shifted to the energy saving mode, the power supply from the specific power source to the image conversion unit 130 is stopped, but the power supply to the CLK supply unit 131 is continued and the first distance measuring element 121 or the second power supply is continued. The operation clock is supplied to only one of the distance measuring elements 121. At this time, the output timing of the unit time of the image signal output from the operating distance measuring element can be changed by lowering the operation clock supplied to the operating distance measuring element. Thereby, it is possible to reduce the power consumption of the distance measuring element providing the through image.

  In other words, the specific power source refers to a power source that must be turned on / off in the specification of the IC that constitutes the image conversion unit 130 or a power source that consumes a large amount of power.

  Next, an example of the transition process to the energy saving mode of the distance measuring device 100 according to the present embodiment will be described with reference to the flowchart of FIG. In FIG. 7, each step is expressed as S101, S102. In order to shift to the energy saving mode, first, the image conversion unit 130 outputs a sleep instruction signal to the first distance measuring element 121 and the second distance measuring element 122 according to an instruction from the main control unit 10 (S101). Next, a wait process is performed to wait for a sufficient time necessary for the first distance measuring element 121 and the second distance measuring element 122 to shift to the sleep operation (S102). After a necessary and sufficient predetermined time has elapsed, the main control unit 10 instructs the image conversion unit 130 to stop the operation (S103). Next, a Wait process is performed to wait for a sufficient time necessary for the image conversion unit 130 to stop operating (S104). After the necessary and sufficient predetermined time has elapsed, the main control unit 10 instructs the CLK supply unit 131 to stop outputting the operation reference CLK to the image conversion unit 130 (S105). Next, a wait process is performed in which the power supply control unit 132 waits for an elapse of time necessary and sufficient for preparation for stopping the CLK (S106). After the necessary and sufficient predetermined time has elapsed, the main control unit 10 instructs the power supply control unit 132 to stop the output of the specific power supply that supplies power to the image conversion unit 130 and the CLK supply unit 131 (S107). .

  Through the processing steps S101 to S107, the distance measuring device 100 shifts the first distance measuring element 121 and the second distance measuring element 122 to the sleep mode, stops the operation clock of the image conversion unit 130, and is not used for real-time processing. Stop supplying specific power. Thereafter, the state of the energy saving mode is continued until a “start-up instruction” for shifting to the operation mode for performing the AF process is notified from the main control unit 10 (No in S108). After the start instruction from the main control unit 10 (Yes in S108), the distance measuring device 100 returns from the energy saving mode and shifts to the normal operation mode (normal mode).

  In step S101, the sleep operation of the first distance measuring element 121 and the second distance measuring element 122 that has received the sleep instruction signal from the image conversion unit 130 according to the instruction of the main control unit 10 is the image transfer rate in the normal mode. An operation of outputting an image at an image transfer rate lower than (frame rate) may be used. In this case, the number of images transferred from the first distance measuring element 121 and the second distance measuring element 122 to the main control unit 10 via the image conversion unit 130 is smaller than that in the normal mode. The power consumption of the element 121 and the second distance measuring element 122 can be reduced.

  Next, an example of return control from the energy saving mode of the distance measuring apparatus 100 according to the present embodiment will be described with reference to the flowchart of FIG. In FIG. 8, each processing step is represented as S201, S202. When the imaging apparatus 1 shifts to an operation mode that requires AF processing, the main control unit 10 notifies the image conversion unit 130 of an activation instruction. The image conversion unit 130 that has been notified of the start instruction starts the process of shifting from the power saving mode to the normal operation mode.

  First, the main control unit 10 instructs the power supply control unit 132 to start output so as to start the supply of power from the specific power supply to the image conversion unit 130 and the CLK supply unit 131 (S201). After the output start instruction, a wait process is performed to wait for a sufficient and sufficient time until the power supply from the specific power source is started to the image conversion unit 130 (S202). After a necessary and sufficient predetermined time has elapsed, transfer of circuit information from the main control unit 10 to the image conversion unit 130 is started (S203). Next, the image conversion unit 130 expands the transferred circuit information to prepare for operation in the transferred circuit. When the operation preparation is completed, the image conversion unit 130 notifies the main control unit 10 of a preparation completion signal (YES in S204). The main control unit 10 waits for processing until a preparation completion signal is notified (NO in S204). After the preparation completion signal is notified to the main control unit 10, the main control unit 10 instructs the CLK supply unit 131 to start outputting the operation reference CLK to the image conversion unit 130 (S205). Next, a wait process is performed to wait for the elapse of a sufficient time until the CLK supplied from the CLK supply unit 131 to the image conversion unit 130 is stabilized (S206). After the necessary and sufficient predetermined time has elapsed, the image conversion unit 130 performs an initial setting process from the main control unit 10 (S207).

  Next, an activation instruction is notified from the main control unit 10 to the first distance measuring element 121 and the second distance measuring element 122 via the image conversion unit 130 (S208). The first distance measuring element 121 and the second distance measuring element 122 that have received the activation instruction perform an initial setting process (S209). Next, a wait process is performed to wait for a sufficient amount of time until the image output from the first distance measuring element 121 and the second distance measuring element 122 is stabilized (S210). Whether or not the image synchronization signals from the first distance measuring element 121 and the second distance measuring element 122 are correctly output with respect to the initially set values after the necessary and sufficient predetermined time has elapsed. Is performed (S211). If the image synchronization signal is correctly output, the activation process of the image conversion unit 130 ends (YES in S211). The process is repeated until the image synchronization signal is correctly output (NO in S211).

  If the image transfer rates of the first distance measuring element 121 and the second distance measuring element 122 are lowered at the time of shifting to the energy saving mode, the image transfer rate is set to the image transfer rate in the normal mode in the initial setting process in the process 209. To rate.

  Next, FIG. 9 shows an example of a timing chart when the distance measuring device 100 shifts to the energy saving mode. The main control unit 10 that has detected that the imaging apparatus 1 has shifted to an operation mode that does not require AF processing starts the shift processing to the energy saving mode for the image conversion unit 130.

  When the transition process to the energy saving mode is started, the image conversion unit 130 is accessed from the main control unit 10 via the SIO to the internal register, and a reset signal (for the first distance measuring element 121 and the second distance measuring element 122 ( Video_RESET1 and Video_RESET2) are negated. Thereafter, the CLK output EN signal (Video_MCLK_EN) for the first distance measuring element 121 and the second distance measuring element 122 is negated from the main control unit 10 to the image conversion unit 130. The image conversion unit 130 detects the negation of Video_MCLK_EN, and stops supplying the operation clock (Video_MCLK) to the first distance measuring element 121 and the second distance measuring element 122. After that, the image conversion unit 130 accesses the internal register from the main control unit via the SIO, and sends the sleep mode transition instruction signals (Video_STBY1 and Video_STBY2) to the first distance measuring element 121 and the second distance measuring element 122. Negate. As a result, the first distance measuring element 121 and the second distance measuring element 122 shift to the sleep state. Next, the RESET signal is negated from the main control unit 10 to the image conversion unit 130, and the image conversion unit 130 stops the operation of the internal main circuit. Subsequently, the CLK supply unit 131 negates the EN signal (CLK_EN) for supplying the operation reference CLK to the image conversion unit 130 from the main control unit 10, and stops the CLK supply to the image conversion unit 130. As a result, the image conversion unit 130 stops all operations of the internal circuit. Thereafter, “POWER25V_EN” instructing the image conversion unit 130 to supply specific power to the power control unit 132 is negated from the main control unit 10, and supply of specific power to the image conversion unit 130 and the CLK supply unit 131 is stopped. The As a result, the image conversion unit 130 shifts to a sleep state (energy saving mode).

  Next, FIG. 10 shows an example of a timing chart when the distance measuring device 100 returns from the energy saving mode to the normal operation mode. When the imaging apparatus 1 shifts to an operation mode that requires AF processing, the main control unit 10 notifies the image conversion unit 130 of an activation instruction. The image conversion unit 130 that has been notified of the start instruction starts the process of shifting from the power saving mode to the normal operation mode.

  When the transition process to the normal mode is started, “POWER25V_EN” instructing the power supply control unit 132 from the main control unit 10 to supply the specific power to the image conversion unit 130 and the CLK supply unit 131 is asserted, and the image Supply of specific power to the conversion unit 130 is started. Since the supply of power has a slight time lag, it waits for a sufficient time for a specific power supply to start supplying. After a sufficient time has elapsed to start supplying the specific power, a circuit information transfer sequence formed inside the image conversion unit 130 is performed.

  Specifically, after the nCONFIG signal is asserted by the main control unit 10 and the output signal (nSTATUS signal) from the image conversion unit 130 is asserted, circuit information is sent from the main control unit 10 to the image conversion unit 130. Transferred. The circuit information is transferred using serial communication with a specific port of the image conversion unit 130.

  After all the circuit information is transferred to the image conversion unit 130, the CONFIG_DONE signal is asserted from the main control unit 10 to the image conversion unit 130, thereby confirming that the circuit information has been transferred normally. The part 10 can be detected. After notifying the main control unit 10 of the completion of the transfer of circuit information, the image conversion unit 130 expands the circuit information to the inside and asserts an INIT_DONE signal for notifying that the user can be accessed. .

  The main control unit 10 starts accessing the image conversion unit 130 after confirming the assertion of the INIT_DONE signal. First, the main control unit 10 asserts CLK_EN, which is a supply EN signal of the operation reference CLK to the image conversion unit 130, with respect to the CLK supply unit 131 to start supplying CLK to the image conversion unit 130. After that, it waits for a time until the supply clock from the CLK supply unit 131 to the image conversion unit 130 is sufficiently stabilized, the RESET signal to the image conversion unit 130 is asserted, and the user circuit based on the previously transferred circuit information The operation starts.

  As described above, when the operation of the distance measuring device 100 is started, the initialization process of the control register of the image conversion unit 130 is performed, and then the first distance measuring element 121 and the second distance measuring element 122 are started up. Processing is performed.

  The image conversion unit 130 accesses the internal register from the main control unit 10 via SIO, and asserts sleep instruction signals (Video_STBY1 and Video_STBY2) for the image sensor 121 and the second distance measuring element 122. As a result, the first distance measuring element 121 and the second distance measuring element 122 return from the sleep mode (energy saving mode). Next, the main control unit 10 asserts the CLK output EN signal, and the image conversion unit 130 detects this, and starts supplying Video_MCLK to the first distance measuring element 121 and the second distance measuring element 122.

  Furthermore, the image conversion unit 130 accesses the internal register from the main control unit 10 via the SIO, and asserts reset signals (Video_RESET1 and Video_RESET2) for the first distance measuring element 121 and the second distance measuring element 122. Thereafter, the main control unit 10 performs initial setting processing for the first distance measuring element 121 and the second distance measuring element 122 via the image conversion unit 130 via the SIO I / F, and starts image acquisition.

  Thereafter, after a sufficient time has elapsed until the image output from each distance measuring element is stabilized, the image conversion unit 130 initializes the image synchronization signals from the first distance measuring element 121 and the second distance measuring element 122. If the process for confirming whether the numerical value is correctly output is performed and the image synchronization signal is normal, the activation process of the distance measuring device 100 is completed.

  Next, still another embodiment of the distance measuring apparatus according to the present invention will be described with reference to the drawings. FIG. 11 is a block diagram of the distance measuring apparatus according to the present embodiment. The distance measuring apparatus 100 according to the embodiment described above (see FIG. 5) includes a CLK supply unit 131 and a power supply control unit 132, and the CLK supply unit 131 responds to an instruction from the main control unit 10. The operation reference clock of the image conversion unit 130 is supplied, and the power control unit 132 supplies the operation power from the specific power source to the image conversion unit 130 and the CLK supply unit 131 in response to an instruction from the main control unit 10. And was going to stop. On the other hand, as shown in FIG. 11, the distance measuring device 100a according to the present embodiment provides power from a specific power source to the image conversion unit 130 from the power control unit 102 included in the main control unit 10a of the imaging device 1a. The operation power is supplied, and the operation reference clock is supplied from the CLK generation / output unit 101 included in the main control unit 10a to the image conversion unit 130.

  Next, an example of the internal configuration of the image conversion unit 130 according to the present embodiment will be described with reference to FIG. The image conversion unit 130 supplies a clock to the first distance measuring element 121 and the second distance measuring element 122 based on the operation reference clock supplied from the CLK generation / output unit 101 of the main control unit 10a. The first distance measuring element 121 and the second distance measuring element 122 output an image of the subject X (see FIG. 3) to the image conversion unit 130 in accordance with the supplied operation clock. In the shift to the energy saving mode of the distance measuring device 100a according to the present embodiment, the main control unit 10a that has detected that the imaging device 1a has shifted to an operation mode that does not require AF processing is an image conversion unit that the distance measuring device 100a includes. The operation clock supply from the CLK generation / output unit 101 is stopped with respect to 130, and then the power supply control unit 102 stops the power supply from the specific power supply to the image conversion unit 130.

  When the distance measuring device 100a returns from the energy saving mode to the normal operation mode, the supply of the specific power to the image conversion unit 130 is started from the power control unit 102 of the main control unit 10a, and then the previous embodiment. Similarly to the distance measuring apparatus 100 according to the above, a transfer sequence of circuit information formed inside the image conversion unit 130 is performed. After the transfer sequence ends normally, supply of the operation reference clock to the image conversion unit 130 is started from the CLK generation / output unit 101 of the main control unit 10a. Thereafter, the operation is started in the user circuit based on the previously transferred circuit information.

  Thus, when the operation of the distance measuring device 100a is started, the initialization process of the control register of the image conversion unit 130 is performed, and then the first distance measuring element 121 and the second distance measuring element 122 are started up. Processing is performed. The image conversion unit 130 confirms that the image output from each distance measuring element is stable and the image synchronization signals from the first distance measuring element 121 and the second distance measuring element 122 are normal, and the distance measuring device 100a The startup process is complete.

  As described above, according to the imaging apparatus of the present invention, the distance measuring element included in the distance measuring apparatus used for the phase difference detection AF method is shifted to the energy saving mode in a mode other than the shooting mode that does not require AF processing. A plurality of power supplies for stopping the operation clock for the image conversion circuit for inputting two images used in the phase difference detection AF method to the main LSI that controls the operation of the imaging apparatus, and for supplying power to the image conversion circuit By stopping the operation power supply from a specific power source among them, it is possible to shorten the return time from the energy saving mode while reducing the power consumption.

  In particular, stopping the operation power supply from a specific power supply eliminates the need for startup and shutdown processes based on the sequence of multiple power supplies, so the overall processing time required for mode transition can be increased. Reduction of power consumption, simplification of the image conversion circuit configuration, and simplification of the control flow can be achieved at the same time.

DESCRIPTION OF SYMBOLS 10 Main control part 121 Distance measuring element 122 Distance measuring element 130 Image conversion part 131 CLK supply part 132 Power supply control part

JP 2001-221945 A JP 2003-107326 A

Claims (14)

A ranging device capable of transitioning between a normal mode and a power saving mode,
A first distance measuring lens and a second distance measuring lens that image incident light from a subject;
A first distance measuring element that outputs a first distance measurement signal corresponding to a subject image formed by the first distance measuring lens; and a second distance measurement corresponding to a subject image formed by the second distance measuring lens. A second ranging element for outputting a distance signal;
With
The main controller that identifies the distance to the subject based on the first distance signal and the second distance signal can be notified.
An image conversion unit for converting the first ranging signal and the second ranging signal for an interface of the main controller;
A power control unit for controlling the power supplied to the image conversion unit;
Having
The distance measuring apparatus, wherein the power control unit stops power supply to the image conversion unit when shifting from the normal mode to the power saving mode. A plurality of power supplies for driving the image conversion unit,
The power control unit stops power supply from some of the plurality of power supplies;
The distance measuring device according to claim 1. A clock supply unit for supplying operation clocks of the first distance measuring element and the second distance measuring element via the image conversion unit;
The power supply control unit stops the power supply to the clock supply unit when shifting from the normal mode to the power saving mode, and causes the clock supply unit to stop supplying the operation clock.
The distance measuring device according to claim 1 or 2. A clock supply unit for supplying operation clocks of the first distance measuring element and the second distance measuring element via the image conversion unit;
The clock supply unit stops supplying the operation clock to one of the first distance measuring element and the second distance measuring element when shifting from the normal mode to the power saving mode.
The distance measuring device according to claim 1 or 2. The main control device is connected to a display, and displays an image corresponding to a distance measurement signal output by a distance measuring element that is not stopped from supplying the operation clock among the first distance measuring element and the second distance measuring element. Display on the above display,
The distance measuring device according to claim 4. The output timing of the ranging signal output per unit time by the first ranging element and the second ranging element can be changed.
The distance measuring device according to claim 1. A ranging device capable of transitioning between a normal mode and a power saving mode,
A distance measuring lens that focuses incident light from the subject;
A distance measuring element that outputs a distance measuring signal corresponding to a subject image formed by the distance measuring lens;
With
Can be notified with the main controller that identifies the distance to the subject based on the ranging signal,
An image converter for converting the distance measurement signal for an interface of the main controller;
A power control unit for controlling the power supplied to the image conversion unit;
Having
The power supply control unit stops a part of the power supplied to the image conversion unit when shifting from the normal mode to the power saving mode. A plurality of power supplies for driving the image conversion unit,
The power control unit stops power supply from some of the plurality of power supplies;
The distance measuring device according to claim 7. A clock supply unit that supplies an operation clock of the distance measuring element via the image conversion unit;
The power supply control unit stops the power supply to the clock supply unit when shifting from the normal mode to the power saving mode, and causes the clock supply unit to stop supplying the operation clock.
The distance measuring device according to claim 7 or 8. An imaging optical system comprising: an imaging lens that forms an incident light from a subject; and an imaging element that outputs an imaging signal corresponding to the subject image formed by the imaging lens;
A distance measuring optical system comprising: a distance measuring lens that forms incident light from the subject; and a distance measuring element that outputs a distance measuring signal corresponding to the subject image formed by the distance measuring lens;
A main control unit that specifies a distance to the subject based on the distance measurement signal and calculates a movement amount of the imaging lens;
A focusing unit for moving the imaging lens in the optical axis direction based on the calculated movement amount;
An imaging device comprising:
The imaging apparatus according to claim 1, wherein the ranging optical system is a ranging apparatus according to claim 1. A first distance measuring lens and a second distance measuring lens that form incident light from a subject, and a first distance measuring signal that outputs a first distance measurement signal corresponding to the subject image formed by the first distance measuring lens. And a second distance measuring element that outputs a second distance signal corresponding to the subject image formed by the second distance measuring lens, the first distance signal and the second distance signal. An image conversion unit that can notify the main control device that specifies the distance to the subject based on the first distance measurement signal and the second distance measurement signal for an interface of the main control device; Executed in a distance measuring apparatus that includes a power source control unit that controls power supplied to the image conversion unit and a plurality of power sources that drive the image conversion unit and that can be switched between a normal mode and a power saving mode. A possible ranging method,
When shifting from the normal mode to the power saving mode,
The distance measuring method, wherein the power control unit stops a part of power supplied to the image conversion unit. The distance measuring device includes a clock supply unit that supplies an operation clock to the first distance measuring element and the second distance measuring element via the image conversion unit,
When shifting from the normal mode to the power saving mode,
The power control unit stopping power supply to the clock supply unit;
The clock supply unit stopping the supply of the operation clock;
The distance measuring method according to claim 11, further comprising: A first distance measuring lens and a second distance measuring lens that form incident light from a subject, and a first distance measuring signal that outputs a first distance measurement signal corresponding to the subject image formed by the first distance measuring lens. An apparatus comprising: an element; and a second distance measuring element that outputs a second distance signal corresponding to a subject image formed by the second distance lens.
10. A distance measuring program that functions as the distance measuring device according to claim 1. An imaging optical system comprising: an imaging lens that forms an incident light from a subject; and an imaging element that outputs an imaging signal corresponding to the subject image formed by the imaging lens;
A distance measuring optical system comprising: a distance measuring lens that forms incident light from the subject; and a distance measuring element that outputs a distance measuring signal corresponding to the subject image formed by the distance measuring lens;
A main control unit that specifies a distance to the subject based on the distance measurement signal and calculates a movement amount of the imaging lens;
A focusing unit for moving the imaging lens in the optical axis direction based on the calculated movement amount;
An imaging device equipped with
An imaging program that functions as the imaging apparatus according to claim 10.

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