JP2008009224A - Imaging system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging system and an imaging method that detect a contact object on a lens. <P>SOLUTION: The imaging system 10 includes at least two or more transparent conductive films 14 and 16 on a lens 12 for an optical system 216. A voltage is applied by a voltage apply part 18 in between the conductive films, simultaneously, the voltage at the conductive films is detected by a voltage detection part 20, and a change in the detection voltage related to the apply voltage is judged by a judging part 22, then, the contact object on the lens 12, for example, such a state that an operator's finger touches the lens 12 or the surface of the lens 12 is soiled with dust or oil can be detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging system, an imaging method, and a lens unit used for them.

  Conventionally, in an imaging system, if dirt such as dust or oil adheres to the lens, or if an operator's finger hits and there is a contact object on the lens, the image taken is blurred and a clear image is obtained. Can't get. Therefore, the user needs to confirm the presence or absence of dirt on the lens by visual inspection.

In addition, some imaging systems have a configuration in which, for example, a lens is disposed at an end. In this case, a user's finger is likely to be placed on the lens, and dirt is also likely to adhere.
JP 2002-277928 A JP 2001-119614

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an imaging system and an imaging method for detecting a contact object on a lens of an imaging system, and a lens unit used for the same, which eliminates the disadvantages of the prior art.

  In order to solve the above-described problems, the present invention provides an imaging system that captures a desired object scene image incident through an optical system including a lens, on the surface of the lens disposed on the outermost side of the optical system. At least two or more transparent conductive films that do not affect the optical system are formed in advance, voltage applying means for applying a predetermined voltage to these transparent conductive films, and voltage detection for detecting the voltage in these transparent conductive films And a determination means for determining the voltage information detected by the voltage detection means and detecting the presence or absence of a contact object on the lens.

  In addition, an imaging method in an imaging system that captures a desired object scene image incident through an optical system including a lens affects the optical system on the surface of the lens arranged on the outermost side in the optical system. At least two or more transparent conductive films that are not formed in advance, a voltage application step for applying a predetermined voltage to these transparent conductive films, a voltage detection step for detecting voltages in these transparent conductive films, and this voltage detection And determining the voltage information detected in the process to detect the presence or absence of a contact object on the lens.

  Moreover, the lens unit including the lens provided in the optical system in the imaging system forms at least two or more transparent conductive films that do not affect the optical system on the surface of the lens. In connection with the terminals, these terminals are used to apply a predetermined voltage between these two or more transparent conductive films and to detect the voltage between these two or more transparent conductive films In addition, these transparent conductive films are characterized in that, when a predetermined voltage is applied, if there is a contact on the lens, the voltage is changed and detected.

  According to the imaging system of the present invention, the lens of the optical system includes at least two or more transparent conductive films, and the voltage application unit applies a voltage to these conductive films, while the voltage detection unit applies the voltage in the conductive film. By detecting the voltage change, the determination unit determines that the contact object on the lens, for example, the finger of the operator touches the lens, or that the lens has dirt such as dust or oil. be able to.

  According to the present invention, the imaging system can warn the operator that there is a contact object such as dirt on the lens according to the determination result indicating the presence or absence of the contact object by the determination unit.

  Furthermore, according to the present invention, by forming a cover conductor on the back side of the lens cover of the imaging system, by determining a change in the capacitance of the capacitor composed of the cover conductor and the transparent conductor on the lens, A contact on the lens can be detected.

  Next, an embodiment of an imaging system according to the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, the imaging system 10 in the present embodiment includes at least two transparent conductive films 14 and 16 in a lens 12 provided in an optical system, and a voltage application unit 18 is connected to these conductive films. While the voltage is applied, the voltage detection unit 20 detects the voltage of the conductive film, and the determination unit 22 determines the detected voltage information, thereby detecting the contact object on the lens 12. Note that portions not directly related to understanding the present invention are not shown and redundant description is avoided.

  As shown in FIG. 2, the imaging system 10 of this embodiment includes a shutter button 202, a mode switch 204, a power source 206, a system control unit 208, a timing generator 210, an AE (Automatic Exposure) driving unit 212, and an AF. (Automatic Focus) The optical system 216 including the lens 12, aperture 218 and AF unit 220, image sensor 222, pre-processing unit 224, analog / digital conversion unit 226, bus 228, AF The system 10 includes a detection unit 230, an AE detection unit 232, an image processing unit 234, a memory 236, a compression processing unit 238, a recording unit 240, and an image display unit 242, but the system 10 is not limited to this configuration. An imaging system may be used.

  The lens 12 of the present embodiment is arranged on the outermost side among a number of lenses provided in the optical system 216. The system 10 can be used to contact the surface of the lens 12 by the operator, Detects dirt, oil, and other dirt attached to the surface. For example, as illustrated in FIG. 3, in the imaging system 10 in which the lens 12 is disposed at the end, when the lens cover 252 is open, the operator's finger is likely to be applied to the lens 12 and easily contaminated.

  The transparent conductive films 14 and 16 of the present embodiment may be formed of a transparent conductive film material that does not affect the optical system, such as a titanium oxide (TiO) film. Further, at least two transparent conductive films 14 and 16 are formed on the surface of the lens 12 by a film forming method such as coating, vapor deposition, and sputtering. The transparent conductive films 14 and 16 are not limited to these materials, and may be formed of various transparent conductive film materials, and are not limited to these methods, and may be formed by various film forming methods.

  The transparent conductive films 14 and 16 are arranged so as to be able to detect when there is a contact object at any position on the lens 12, for example, at least one of the films 14 is near the outer periphery of the lens 12 and the other film 16 is the lens. Formed near the center of 12.

  The voltage application unit 18 applies a predetermined AC voltage 102 between the transparent conductive films 14 and 16, and can be connected to the determination unit 22 to notify the applied voltage value 104. The voltage application unit 18 may generate the applied voltage 102 in accordance with the supply voltage from the power source 206 of the system 10.

  The voltage detector 20 measures the voltage value 106 in the resistor 24 disposed between the transparent conductive film 16 and the voltage application unit 18, and indicates voltage information indicating a voltage change due to a change in impedance between the conductive films 14 and 16. The voltage information 108 is supplied to the determination unit 22. The detection unit 20 may generate the voltage information 108 after analog / digital conversion of the voltage value 106.

  The determination unit 22 determines a change in voltage indicated by the voltage information 108 from the voltage detection unit 20, for example, by determining a change rate of the voltage information 108 with respect to the applied voltage value 104 from the voltage application unit 18, thereby Detect the presence or absence of contact objects. The determination unit 22 may be included in the system control unit 208 of the system 10, and may be operated by a central processing unit (CPU) included in the control unit 208.

  For example, the determination unit 22 compares the phase of the voltage or current of the applied voltage value 104 and the voltage information 108 and determines that there is no contact object when the phase difference is smaller than a predetermined comparison value. In the case, it is determined that there is a contact object.

  Further, the system 10 has a warning function, and can warn the operator that there is a contact object on the surface of the lens 12 according to the determination result by the determination unit 22. The system 10 may emit a warning sound such as a buzzer or display a warning on the screen display unit 242 as a warning function.

  Further, the system 10 may have a function of automatically cleaning the lens or a function of not starting imaging by disabling the shutter when the determination result by the determination unit 22 is a contact object.

  In the present embodiment, the lens unit including the lens 12 and the transparent conductive films 14 and 16 may be configured independently of the circuit portion including the voltage application unit 18, the voltage detection unit 20, the determination unit 22, and the resistor 24. . For example, this lens unit has terminals connected to the conductive films 14 and 16, respectively, and these terminals are configured to be connected to a connector 26 provided in the circuit portion to enable voltage application and voltage detection. The

  Next, the operation of detecting a contact object on the lens in the imaging system 10 of the present embodiment will be described with reference to the flowchart of FIG.

  In the present system 10, first, a predetermined AC voltage 102 is applied between the transparent conductive films 14 and 16 by the voltage application unit 18 (step S122). The applied voltage value 104 is also notified to the determination unit 22.

  On the other hand, in the present system 10, the voltage detection unit 20 detects the voltage value between the transparent conductive films 14 and 16 (step S124). At this time, in this embodiment, the voltage value 106 at the resistor 24 is measured, and processing such as analog / digital conversion is performed to detect the voltage information 108. This voltage information 108 is supplied to the determination unit 22.

  Next, the process proceeds to step S126, where the determination unit 22 compares the applied voltage value 104 and the phase of the voltage or current of the voltage information 108 to determine. Here, when the phase difference is smaller than a predetermined comparison value, it is determined that there is no contact object on the lens 12, and for example, the lens contact object detection is repeated by returning to step S124. It is determined that there is a contact on the lens 12 (step S128).

  If it is determined in step S128 that there is a contact object on the lens 12, for example, the process proceeds to step S130, and the warning function of the present system 10 is executed according to the determination result by the determination unit 22 to the operator. A warning is made that there is a contact on the lens.

  As another example, the transparent conductive films 14 and 16 in the present system 10 are formed in a radial pattern so as not to overlap each other on the surface of the lens 12 as shown in FIG. The conductive film 16 near the center of the lens 12 may be formed toward the center of the lens 12 and toward the outer periphery of the lens 12.

  As another embodiment, the transparent conductive films 14 and 16 in the present system 10 are formed in a spiral shape so as not to overlap each other on the surface of the lens 12 as shown in FIG. The conductive film 16 near the center of the lens 12 may be formed toward the outer periphery of the lens 12. In FIG. 7, the conductive films 14 and 16 are substantially composed of a plurality of circular curves, and each circle has a different radius. However, the conductive films 14 and 16 may be formed in a spiral shape that gradually changes the radius.

  Furthermore, as another example, the present system 10 not only forms the transparent conductive films 14 and 16 on the surface of the lens 12, but also on the back side of the lens cover 252 of the present system 10 as shown in FIGS. The conductor 256 is formed so that when the lens cover 252 is closed, the cover conductor 256 faces the surfaces of the on-lens transparent conductive films 14 and 16 with a predetermined distance, as shown in FIG. Formed.

  The cover conductor 256 has a shape that includes at least the range of the surfaces of the on-lens transparent conductive films 14 and 16, and may have the same shape as the outer surface of the lens 12. The cover conductor 256 may be formed of a transparent conductive film, but any other non-transparent conductor may be used.

  The cover conductor 256 and the on-lens transparent conductive films 14 and 16 form a capacitor having a capacitance according to a predetermined distance. However, if there is a contact on the lens 12, the capacitance changes. Therefore, the determination unit 22 determines the change in the capacitance and detects the presence or absence of the contact object of the lens 12.

It is a block diagram which shows one Example of the imaging system which concerns on this invention. It is a block diagram which shows the imaging system of the Example shown in FIG. 1 in detail. It is a figure which shows the external appearance of the imaging system of the Example shown in FIG. It is a figure which shows the external appearance of the imaging system of the Example shown in FIG. It is a flowchart which shows the operation | movement procedure of the imaging system of the Example shown in FIG. It is a figure which shows the other example of formation of the transparent conductive film of the imaging system which concerns on this invention. It is a figure which shows the other example of formation of the transparent conductive film of the imaging system which concerns on this invention. It is a figure which shows the other example of formation of the transparent conductive film of the imaging system which concerns on this invention.

Explanation of symbols

10 Imaging system
12 Lens
14, 16 Transparent conductive film
18 Voltage application section
20 Voltage detector
22 Judgment part
24 resistance
26 Connector

Claims (23)

In an imaging system that captures a desired object scene image incident through an optical system including a lens, the system includes:
At least two or more transparent conductive films that do not affect the optical system are formed in advance on the surface of the lens arranged on the outermost side in the optical system,
Voltage applying means for applying a predetermined voltage to the transparent conductive film;
Voltage detecting means for detecting a voltage in the transparent conductive film;
An imaging system comprising: determination means for determining voltage information detected by the voltage detection means and detecting the presence or absence of a contact object on the lens.   The imaging system according to claim 1, wherein the transparent conductive film is a titanium oxide film.   2. The imaging system according to claim 1, wherein among the two or more transparent conductive films, the system includes a first transparent conductive film formed near an outer periphery of the lens, and a second transparent conductive film serving as the lens. An imaging system characterized by being formed in the vicinity of the center.   4. The imaging system according to claim 3, wherein the two or more transparent conductive films are radially formed on the surface of the lens so as not to overlap each other, the first transparent conductive film faces the center of the lens, An imaging system, wherein a transparent conductive film is formed so as to face an outer periphery of the lens.   4. The imaging system according to claim 3, wherein the two or more transparent conductive films are formed in a spiral shape so as not to overlap each other on the surface of the lens, the first transparent conductive film faces the center of the lens, and the second The transparent conductive film is formed so as to face the outer periphery of the lens.   The imaging system according to claim 1, wherein the voltage detection unit generates the voltage information by measuring a voltage at a resistor arranged between the transparent conductive film and the voltage application unit. system.   2. The imaging system according to claim 1, wherein the determination unit compares the phase of the predetermined voltage and the voltage or current indicated by the voltage information, and if the phase difference is smaller than a predetermined comparison value, the lens. An imaging system characterized by determining that there is no contact object on the top and determining that there is a contact object in other cases. The imaging system according to claim 1, wherein the system includes a lens cover for protecting the lens,
The lens cover is formed with a conductor on the back side,
The conductor is formed to face the surface of the transparent conductive film at a predetermined distance when the lens cover is closed,
The determination unit determines a change in capacitance between the conductor and the transparent conductive film, and detects the presence or absence of a contact object on the lens according to the change. The imaging system according to claim 1, wherein the system includes warning means for issuing a warning that there is a contact object on the lens,
The imaging system according to claim 1, wherein the warning unit issues the warning according to a determination result by the determination unit. In an imaging method in an imaging system for imaging a desired object scene image incident through an optical system including a lens, the method includes:
On the surface of the lens arranged on the outermost side in the optical system, at least two or more transparent conductive films that do not affect the optical system are formed in advance,
A voltage applying step of applying a predetermined voltage to the transparent conductive film;
A voltage detection step of detecting a voltage in the transparent conductive film;
And a determination step of determining presence or absence of a contact object on the lens by determining voltage information detected in the voltage detection step.   The imaging method according to claim 10, wherein the transparent conductive film is a titanium oxide film.   11. The imaging method according to claim 10, wherein, of the two or more transparent conductive films, the first transparent conductive film is formed near an outer periphery of the lens, and the second transparent conductive film is the lens. An imaging method characterized by being formed near the center of the image.   13. The imaging method according to claim 12, wherein the two or more transparent conductive films are formed in a radial pattern so as not to overlap each other on the surface of the lens, and the first transparent conductive film faces the center of the lens, An imaging method, wherein the transparent conductive film is formed so as to face an outer periphery of the lens.   13. The imaging method according to claim 12, wherein the two or more transparent conductive films are formed in a spiral shape so as not to overlap each other on the surface of the lens, the first transparent conductive film faces the center of the lens, and the second The transparent conductive film is formed so as to face the outer periphery of the lens.   The imaging method according to claim 10, wherein in the voltage detection step, the voltage information is generated by measuring a voltage at a resistor arranged in connection with the transparent conductive film.   The imaging method according to claim 10, wherein the determination step compares the phase of the predetermined voltage and the voltage or current indicated by the voltage information, and the lens has a phase difference smaller than a predetermined comparison value. An imaging method characterized by determining that there is no contact object on the top and determining that there is a contact object in other cases. The imaging method according to claim 10, wherein the method comprises:
Forming a conductor in advance on the back side of the lens cover that protects the lens,
The conductor is formed to face the surface of the transparent conductive film at a predetermined distance when the lens cover is closed,
In the imaging method, the determination step determines a change in electrostatic capacitance between the conductor and the transparent conductive film, and detects presence or absence of a contact object on the lens according to the change. The imaging method according to claim 10, further comprising a warning step of issuing a warning that there is a contact object on the lens,
The imaging method according to claim 1, wherein the warning step issues the warning according to a determination result of the determination step. In a lens unit including a lens provided in an optical system in an imaging system, the unit includes:
Forming at least two transparent conductive films that do not affect the optical system on the surface of the lens;
Each of the transparent conductive films is connected to a terminal, and these terminals apply a predetermined voltage between the two or more transparent conductive films, and a voltage between the two or more transparent conductive films. Used to detect,
The transparent conductive film may be detected by changing the voltage when there is a contact on the lens when the predetermined voltage is applied.   The lens unit according to claim 19, wherein the transparent conductive film is a titanium oxide film.   20. The lens unit according to claim 19, wherein among the two or more transparent conductive films, the unit has a first transparent conductive film formed in the vicinity of an outer periphery of the lens, and the second transparent conductive film is the lens. A lens unit formed near the center of the lens.   The lens unit according to claim 21, wherein the two or more transparent conductive films are formed in a radial shape so as not to overlap each other on the surface of the lens, and the first transparent conductive film faces the center of the lens, A lens unit, wherein the transparent conductive film is formed so as to face the outer periphery of the lens. 23. The lens unit according to claim 21, wherein the two or more transparent conductive films are formed in a spiral shape that does not overlap each other on the surface of the lens, the first transparent conductive film faces the center of the lens, and the second The transparent conductive film is formed so as to face the outer periphery of the lens.