JP2011237533A - Imaging device, and method and program for controlling aperture of imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain accuracy of aperture control even when a reset sensor deteriorates due to secular change, etc.SOLUTION: A system control section 101 excites a stepping motor to a predetermined excitation phase which corresponds to a start position of a reset action of an aperture, clears a positional counter of the aperture, starts a reset drive of the aperture, and then determines whether a reset position is detected or not. When the reset position is detected, an aperture drive correction amount is calculated from the difference between a drive pulse amount for the stepping motor from the start position of the reset action to the detected reset position and a reset drive amount at adjustment stored in a storage section 112, and stored in the storage section 112. When the aperture is driven, a targeted aperture value determined by an AE process, etc. is obtained and converted into a targeted pulse position to calculate a drive pulse position from the targeted pulse position and the aperture drive correction amount stored in the storage section 112.

Description

  The present invention relates to an imaging apparatus that controls the amount of light that passes through a diaphragm by opening and closing a diaphragm blade, a method for controlling the diaphragm of the imaging apparatus, and a program.

  In aperture control of an imaging device that controls the amount of light passing through the aperture by opening and closing the aperture blades with a stepping motor or the like, the aperture is reset when the power is turned on to determine the initial reference position (reset position) of the aperture After that, aperture control is performed (see, for example, Patent Document 1).

  Further, the aperture is adjusted at the time of shipment, and the amount of drive pulses of a stepping motor or the like with reference to each aperture value and the reset position is stored in association with each other. Then, after performing a diaphragm reset operation upon power-on at the time of use, the drive pulse amount associated with a desired diaphragm value is read to drive the diaphragm, thereby maintaining the precision of the diaphragm control.

JP-A-7-111617

  Here, with reference to FIG. 5, the problem when the reset sensor for detecting the reset position of the diaphragm is deteriorated due to aging or the like will be described. FIG. 5 is a graph showing the output of the reset sensor with respect to the aperture driving amount at the time of shipment adjustment and use (when the reset sensor deteriorates), and a diagram showing the change of the aperture driving amount corresponding to each aperture value due to the deterioration of the reset sensor. is there. The horizontal axis of the graph is the aperture driving amount, and the vertical axis is the output of the reset sensor.

  At the time of shipment adjustment, the output of the reset sensor is as indicated by a broken line a in the graph, and the reset position at the time of shipment adjustment is the intersection of the broken line a and the reset detection threshold level. With this reset position as a reference, the aperture drive amount corresponding to each aperture value is stored in association with each other, so that aperture adjustment at the time of shipment is performed.

  When the imaging device is used in a state where the reset sensor has deteriorated due to secular change or the like, the output of the reset sensor is indicated by a solid line b in the graph, and the reset position at that time is indicated by the solid line b, the reset detection threshold level, The intersection of Since the output level of the reset sensor is lowered due to the deterioration of the reset sensor, as indicated by an arrow 500, a deviation occurs between the reset position at the time of shipment adjustment and the reset position at the time of use. Since the aperture drive amount corresponding to each aperture value is based on the reset position, the displacement generated at the reset position causes a displacement in the aperture drive amount corresponding to each aperture value as indicated by the arrow 501.

  As described above, due to the deterioration of the reset sensor, the aperture driving amount corresponding to each aperture value, that is, the aperture diameter of the aperture differs between the time of shipping adjustment and the time of use, so that the accuracy of aperture control cannot be maintained. There is a problem.

  The present invention has been made in view of the above points, and an object of the present invention is to maintain the accuracy of aperture control even when the reset sensor is deteriorated due to secular change or the like.

  An image pickup apparatus according to the present invention includes an aperture control unit that controls the amount of light that passes through the aperture by opening and closing the aperture blades, a reset position detection unit that detects a reset position of the aperture, and a start position of the reset operation of the aperture A drive amount measuring means for measuring a reset drive amount from the reset position detecting means to a reset detection position, a storage means for storing the reset drive amount at the time of adjustment by the drive amount measuring means, and a measurement by the drive amount measuring means And a correction unit that corrects the driving amount of the diaphragm when controlling the amount of light based on a difference between the reset driving amount and the reset driving amount at the time of adjustment stored in the storage unit. To do.

  According to the present invention, it is possible to maintain the accuracy of aperture control even when the reset sensor is deteriorated due to secular change or the like.

It is a block diagram which shows the structure of the imaging device which concerns on embodiment. 5 is a flowchart illustrating a reset operation of a diaphragm of the imaging apparatus according to the embodiment. It is a figure for demonstrating the outline | summary of the correction | amendment of the aperture drive amount by deterioration of the reset sensor of the imaging device which concerns on embodiment. 6 is a flowchart illustrating an aperture driving operation of the imaging apparatus according to the embodiment. It is a graph which shows the output of the reset sensor with respect to the aperture drive amount at the time of shipment adjustment and use (at the time of reset sensor degradation), and a diagram showing the change due to the deterioration of the reset sensor of the aperture drive amount corresponding to each aperture value.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus 100 according to an embodiment to which the present invention is applied. In FIG. 1, reference numeral 100 denotes an image pickup apparatus represented by a digital camera or the like. Reference numeral 101 denotes a system control unit that controls the entire imaging apparatus 100.

  A zoom lens 102 changes the focal length by changing the position in the optical axis direction. Reference numeral 103 denotes a zoom control unit that drives and controls the zoom lens 102.

  Reference numeral 104 denotes a shutter / aperture unit, which has a reset sensor as reset position detection means for detecting a reset position of the aperture. Reference numeral 105 denotes a shutter / aperture control unit which controls the drive of the shutter / aperture unit 104. The shutter / aperture control unit 105 controls the amount of light passing through the aperture by driving the aperture blades to open and close by a stepping motor.

  A focus lens 106 performs focus adjustment by changing the position in the optical axis direction. Reference numeral 107 denotes a focus control unit that drives and controls the focus lens 106.

  Reference numeral 108 denotes an image sensor that converts a light image that has passed through each lens into an electrical signal. A signal processing unit 109 converts the electrical signal output from the image sensor 108 into an image signal and processes it according to the application. Reference numeral 110 denotes a display unit including a liquid crystal display device, a speaker, and the like, and an operation state using characters, images, sounds, and the like based on execution of a program in the system control unit 101 and a signal output from the signal processing unit 109. And messages are displayed.

  An operation unit 111 includes various buttons and inputs various operation instructions to the system control unit 101. Reference numeral 112 denotes a storage unit, which is a memory that stores various data such as constants, variables, programs, and video information for operation of the system control unit 101. The storage unit 112 stores a reset drive amount (a reset drive amount at the time of adjustment) from the start position of the aperture reset operation at the time of shipment adjustment to the reset detection position by the reset sensor.

  Reference numeral 113 denotes a recording unit, which is an electrically erasable / recordable non-volatile memory that records photographing data and the like. Reference numeral 114 denotes a power supply unit that supplies power to the entire imaging apparatus 100 according to the application.

  Next, the operation of the imaging apparatus 100 according to the present embodiment will be described. The operation unit 111 includes a shutter release button configured such that a first switch (hereinafter referred to as SW1) and a second switch (hereinafter referred to as SW2) are sequentially turned on in accordance with the pressing amount. SW1 is turned on when the shutter release button is depressed approximately half, and SW2 is turned on when the shutter release button is depressed to the end.

  When SW1 of the operation unit 111 is turned on, the system control unit 101 performs focus adjustment by driving the focus lens 106 by the focus control unit 107 based on the AF function. Further, the system control unit 101 sets the appropriate exposure amount by driving the shutter / aperture unit 104 by the shutter / aperture control unit 105 based on the AE function.

  Further, when SW2 of the operation unit 111 is turned on, the system control unit 101 converts an electrical signal obtained from the optical image exposed to the image sensor 108 into an image signal by the signal processing unit 109 and performs image processing. Thereafter, the image data subjected to the image processing is stored in the storage unit 112 and is recorded on the recording medium by the recording unit 113.

  Next, with reference to FIG. 2 to FIG. 4, the diaphragm control operation of the imaging apparatus 100 according to the present embodiment will be described. FIG. 2 is a flowchart illustrating a reset operation of the diaphragm of the imaging apparatus 100 according to the embodiment. The diaphragm reset operation shown in the flowchart of FIG. 2 is executed when the imaging apparatus 100 is started up (when the power is turned on).

  In step S201, the system control unit 101 excites the stepping motor to a predetermined excitation phase corresponding to the start position of the aperture reset operation, and then clears the aperture position counter in step S202. Thereby, the drive amount of the diaphragm from the start position of the reset operation to the reset detection position can be measured as the drive pulse amount of the stepping motor. The aperture control is performed via the shutter / aperture control unit 105. The same applies to the subsequent diaphragm control.

  Next, in step S203, the system control unit 101 starts aperture reset driving, and in step S204, determines whether a reset position has been detected. Whether or not the reset position has been detected is determined by whether or not the output of the reset sensor has reached the reset detection threshold level as shown in FIG.

  When the reset position is detected, in step S205, the system control unit 101 stores the drive pulse amount of the stepping motor from the reset operation start position to the reset detection position in the storage unit 112 as the reset drive amount. At the time of shipment adjustment, the reset drive amount is stored in the storage unit 112 as the reset drive amount at the time of adjustment.

  Next, in step S206, the system control unit 101 calculates the aperture drive correction amount from the difference between the reset drive amount during use and the reset drive amount during adjustment obtained in step S205, and ends the aperture reset operation. . The calculated aperture drive correction amount is stored in the storage unit 112.

  Here, correction of the aperture driving amount will be described with reference to FIG. FIG. 3 is a graph showing the output of the reset sensor with respect to the aperture drive amount at the time of shipment adjustment and use (when the reset sensor is deteriorated), and an outline of correction of changes due to deterioration of the reset sensor of the aperture drive amount corresponding to each aperture value. FIG. The horizontal axis of the graph is the aperture driving amount, and the vertical axis is the output of the reset sensor.

  At the time of shipment adjustment, the output of the reset sensor is as indicated by a broken line a in the graph, and the reset position at the time of shipment adjustment is the intersection of the broken line a and the reset detection threshold level. With this reset position as a reference, the aperture drive amount corresponding to each aperture value is stored in association with each other, so that aperture adjustment at the time of shipment is performed.

  When the imaging apparatus 100 is used in a state where the reset sensor has deteriorated due to aging or the like, the output of the reset sensor is indicated by a solid line b in the graph, and the reset position at that time is the solid line b and the reset detection threshold level. Intersection with. Since the output level of the reset sensor is lowered due to deterioration of the reset sensor, a deviation occurs between the reset position at the time of shipment adjustment and the reset position at the time of use. Since the aperture drive amount corresponding to each aperture value uses the reset position as the reference position, the drive amount corresponding to each aperture value also shifts due to the shift generated at the reset position.

  Therefore, when the aperture is driven, the aperture drive correction amount 300 calculated as the difference between the reset position at the time of use and the reset position at the time of shipment adjustment is used to correct the aperture drive amount for each aperture value. It is possible to correct the deviation of the reset position from the time of shipping adjustment.

  FIG. 4 is a flowchart showing the diaphragm drive operation of the imaging apparatus 100 according to the present embodiment. In step S401, the system control unit 101 acquires a target aperture value determined by AE processing or the like, and in step S402, converts the acquired target aperture value into a target pulse position. The conversion from the target aperture value to the target pulse position uses the aperture drive amount stored in association with each aperture value during aperture adjustment at the time of shipment.

  Next, in step S403, the system control unit 101 calculates a drive pulse position from the target pulse position obtained in step S402 and the aperture drive correction amount obtained in step S206 in FIG. Specifically, the drive pulse position is calculated by subtracting the aperture drive correction amount obtained in step S206 of FIG. 2 from the target pulse position obtained in step S402.

  In step S404, the system control unit 101 drives the diaphragm to the driving pulse position calculated in step S403, and ends the diaphragm driving operation.

  As described above, even when the reset sensor is deteriorated due to secular change or the like, it is possible to correct the change in the aperture driving amount due to the secular change or the like of the reset sensor. It becomes possible.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined. Also, when a software program that realizes the functions of the above-described embodiments is supplied from a recording medium directly to a system or apparatus having a computer that can execute the program using wired / wireless communication, and the program is executed Are also included in the present invention. Accordingly, the program code itself supplied and installed in the computer in order to implement the functional processing of the present invention by the computer also realizes the present invention. That is, the computer program itself for realizing the functional processing of the present invention is also included in the present invention. In this case, the program may be in any form as long as it has a program function, such as an object code, a program executed by an interpreter, or script data supplied to the OS. The recording medium for supplying the program may be, for example, a magnetic recording medium such as a hard disk or a magnetic tape, an optical / magneto-optical storage medium, or a nonvolatile semiconductor memory. As a program supply method, a computer program that forms the present invention is stored in a server on a computer network, and a connected client computer downloads and executes the computer program.

  100: imaging device 101: system control unit 102: zoom lens 103: zoom control unit 10: shutter / aperture unit 105: shutter / aperture control unit 106: focus lens 107: focus control unit 108: Image sensor 109: signal processing unit 110: display unit 111: operation unit 112: storage unit 113: recording unit 114: power supply unit

Claims (4)

A diaphragm control means for controlling the amount of light passing through the diaphragm by opening and closing the diaphragm blades;
Reset position detecting means for detecting a reset position of the diaphragm;
Drive amount measuring means for measuring a reset drive amount from a start position of the reset operation of the diaphragm to a reset detection position by the reset position detecting means;
Storage means for storing a reset drive amount at the time of adjustment by the drive amount measuring means;
Correction means for correcting the driving amount of the diaphragm when controlling the amount of light based on the difference between the reset driving amount measured by the driving amount measuring means and the reset driving amount at the time of adjustment stored in the storage means; An imaging apparatus comprising: The aperture control means drives the aperture by a stepping motor,
The imaging apparatus according to claim 1, wherein a start position of the reset operation corresponds to a predetermined excitation phase of the stepping motor. A method for controlling a diaphragm of an imaging device that controls the amount of light passing through the diaphragm by opening and closing the diaphragm blades,
Using reset position detection means for detecting the reset position of the diaphragm, and storage means for storing a reset drive amount from the start position of the reset operation of the diaphragm at the time of adjustment to the reset detection position by the reset position detection means,
A process of measuring a reset drive amount from a start position of the reset operation of the diaphragm to a reset detection position by the reset position detection unit;
And a process of correcting the driving amount of the diaphragm when controlling the amount of light based on the difference between the measured reset driving amount and the reset driving amount at the time of adjustment stored in the storage unit. Method for controlling the aperture of the imaging apparatus. A program for controlling an imaging device that controls the amount of light that passes through the diaphragm by opening and closing the diaphragm blades,
Using reset position detection means for detecting the reset position of the diaphragm, and storage means for storing a reset drive amount from the start position of the reset operation of the diaphragm at the time of adjustment to the reset detection position by the reset position detection means,
A process of measuring a reset drive amount from a start position of the reset operation of the diaphragm to a reset detection position by the reset position detection unit;
In order to cause the computer to execute processing for correcting the driving amount of the diaphragm when controlling the amount of light based on the difference between the measured reset driving amount and the reset driving amount at the time of adjustment stored in the storage unit Program.

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