JP2006129011A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a water pressure applied to a digital camera. <P>SOLUTION: The digital camera 10 has a waterproof structure so as to be usable underwater. A liquid crystal display 14 is arranged on one surface of the body 11 of the digital camera 10. The surface of the display 14 is covered with a display window 13. The rigidity of the display window 13 is lower than that of the camera body 11. On the side of the inside surface of the display window 13, a pressure sensor 20 is arranged so as to face the display window 13. The pressure sensor 20 is capable of detecting a pressure applied to the display window 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital camera capable of detecting water pressure in a digital camera having a waterproof structure.

  Conventionally, a digital camera having a waterproof structure is widely known to be used for underwater photography. In such a digital camera, in order to prevent seawater and the like from entering the inside of the camera body, the inside of the camera body is hermetically sealed and kept on the lens of the digital camera or the camera body surface. The operation member has a structure that can withstand a certain amount of water pressure.

Various digital cameras having such a waterproof structure are known. For example, in the camera described in Patent Document 1, a transparent member is attached to the photographing opening or the like so that water does not enter the photographing optical system. Are known.
JP 2002-277945 A

  By the way, even in the case of a digital camera having a waterproof structure, the range of water pressure that can be used is limited, and when used beyond that water pressure range, the inside of the camera is submerged, causing camera failure. Therefore, for example, in the instruction manual or the like, the usable water depth range is described, and the user can know the usable water depth range.

  However, depending on the usage situation, the camera may be used outside the depth range, but in such cases, it is difficult for the user to recognize that the camera is used beyond the depth range. . Even when a camera is used and breaks down beyond the water depth range, it is difficult to determine the cause of the failure because it is difficult to specify the water depth (water pressure) used during repair.

  Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to provide a digital camera that can easily determine the pressure to be used.

  In a digital camera having a waterproof structure, a digital camera according to the present invention includes a camera body, a liquid crystal display disposed on one surface of the camera body, a display window that covers the surface of the liquid crystal display and has lower rigidity than the camera body. A pressure sensor that faces the display window and can detect the pressure applied to the display window is provided on the inner surface side of the display window.

  The distance between the pressure sensor and the display window is preferably shorter than the distance between the liquid crystal display and the pressure sensor. In this case, even if the display window is pressed by water pressure, the liquid crystal display is not easily pressed by the display window, so that the image quality of the image displayed on the liquid crystal display does not deteriorate.

  The pressure sensor may be in contact with the display window. Preferably, the camera body is formed integrally with the camera body and has a mounting portion provided to face the inner surface of the display window, and the pressure sensor is mounted on the mounting portion. Thus, when water pressure is applied to the camera body, the mounting portion does not substantially deform, while the display window bends to the inner surface side, so that the pressure sensor properly detects the pressure applied to the display window. Can do.

  When the display window has a transparent part that transmits visible light and a shielding part that blocks visible light, the liquid crystal display is provided so as to face the visible part, and the pressure sensor faces the shielding part. Provided.

  It is preferable to provide stop means for stopping the operation of the digital camera when the pressure exceeds the use limit pressure. Moreover, when a pressure is more than the threshold pressure set below a use limit pressure, it is preferable to provide the non-volatile memory which records the pressure value. Further, when the pressure is equal to or higher than a threshold pressure set to be equal to or lower than the use limit pressure, the pressure sensor further includes warning means for issuing a warning and gradually increasing the threshold pressure, and the stop means reaches the threshold pressure, and the pressure is increased. It is more preferable to stop the operation of the digital camera when the pressure exceeds the threshold pressure.

  As described above, in the present invention, since the pressure applied to the digital camera itself can be recognized by detecting the pressure applied to the display window, it is possible to determine under what water pressure the digital camera is used. It can be easily recognized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a rear view of a digital camera to which an embodiment of the present invention is applied. The digital camera 10 has a camera body 11, and an imaging optical system (not shown) is attached to a substantially central portion of the front of the camera body 11.

  A liquid crystal display unit 12 is arranged on the left side of the back surface of the camera body 11. The liquid crystal display unit 12 includes a liquid crystal display 14 and a display window 13. The liquid crystal display 14 displays a still image captured by the imaging optical system. The display window 13 is provided so as to cover the surface of the liquid crystal display 14, and includes a visible portion 13a that transmits visible light and a shielding portion 13b that blocks visible light. The visible portion 13a has a substantially rectangular shape as shown in FIG. 1 according to the shape of the liquid crystal display 14, and the liquid crystal display 14 is provided so as to face the entire visible portion 13a. Therefore, the still image or the moving image displayed on the liquid crystal display 14 can be easily visually recognized by the user.

  A pressure sensor 20 is provided on the inner surface side of the display window 13 so as to face the display window 13. Since the pressure sensor 20 faces the shielding part 13b of the display window 13, the pressure sensor 20 is not visually recognized by the user.

  The pressure sensor 20 is a sheet-like sensor, has a width of about 1 to 5 mm, extends about 2 to 4 cm in the lateral direction of the digital camera 10 (left and right direction in FIG. 1), and has a plurality of detection points. Detection points are provided at intervals of about 1 mm. At each detection point, the electrical resistance value decreases as the pressure applied to the detection point increases. Therefore, the pressure applied to each detection point is detected by detecting the electrical resistance value at each detection point. When no pressure is applied to the detection points, the electric resistance value at each detection point is almost infinite (for example, several MΩ).

  A cross selection switch 15 is provided on the right side of the liquid crystal display unit 12, and an OK switch 16 is provided in the center of the cross selection switch 15. A playback switch 18 and a menu switch 19 are provided above and below the cross selection switch 15, respectively, and a zoom switch 22 is provided above the playback switch 18. In addition, a finder 26 for observing the subject is provided above the liquid crystal display unit 12.

  When the camera body 11 is viewed from the back, a release button 24 is provided on the upper right side of the camera body 11. A power button 25 is provided at a substantially central portion of the upper portion of the camera body 11. A card slot (not shown) is formed on the side surface of the camera body 11. The card slot is provided for inserting a memory card 47 (see FIG. 4) into the camera body 10, and a card connector (not shown) to which the memory card 47 is attached is provided inside the card slot.

  The digital camera 10 has a waterproof structure, and the inside of the camera body 11 is hermetically held with watertightness. However, the digital camera 10 cannot maintain a watertight state inside the camera above a predetermined water pressure (hereinafter referred to as a use limit pressure), and the inside of the camera body 11 is submerged. Therefore, the digital camera 10 should not be used under conditions that exceed the use limit pressure. The water depth corresponding to the use limit pressure is determined as a guaranteed water depth, and the guaranteed water depth is described in, for example, an instruction manual of the digital camera 10.

  2 and 3 are cross-sectional views of the digital camera 10 taken along lines II-II and III-III in FIG. 1, respectively. On the back surface of the camera body 11, a concave portion 32 that is recessed in a rectangular shape on the inner surface side from the outer surface 11 a of the camera body 11 is formed integrally with the camera body 11. The concave portion 32 has a square frame-shaped holder portion 33 whose entire outer periphery is connected to the outer surface 11a. On the inner side of the holder portion 33, a placement portion 30 that is further recessed than the holder portion 33 and an opening portion 31 are formed. The mounting portion 30 is formed in a planar shape and extends along the entire upper frame portion 33 a that forms one side of the rectangular frame within the rectangular frame of the holder 33. The placement unit 30 is formed of the same material as the holder unit 33 (that is, the camera body 11).

  The holder portion 33 is fitted with a rectangular display window 13, whereby the display window 13 is fixed to the camera body 11. The liquid crystal display 14 is provided on the inner surface side of the opening 31 of the recess 32. That is, the still image displayed on the liquid crystal display 14 is visually recognized by the user through the opening 31 and the visible portion 13 a of the display window 13.

  The mounting portion 30 forms a slight gap with the display window 13 in a state where the display window 13 is fitted to the holder portion 33, and in this embodiment, the pressure sensor 20 is provided in this gap. That is, the pressure sensor 20 is placed on the placement unit 30, and the pressure sensor 20 is sandwiched between the display window 13 and the placement unit 30. As a result, the pressure sensor 20 contacts the display window 13.

  The camera body 11 is made of a highly rigid metal. On the other hand, the display window 13 is formed of, for example, an acrylic resin whose rigidity is lower than that of the metal forming the camera body 11. Here, when the digital camera 10 is used, for example, in a normal state, that is, in the atmospheric pressure, no pressure higher than the atmospheric pressure is applied to the camera body 11 and the display window 13. Accordingly, since the display window 13 is not pushed inward, no pressure is applied to the pressure sensor 20, and the electric resistance value at each detection point of the pressure sensor 20 remains almost infinite (several MΩ). .

  However, when the digital camera 10 is used underwater, water pressure acts on the entire digital camera 10 according to the depth of the water. Accordingly, a certain amount of water pressure is applied to the camera body 11 and the display window 13. Here, since the rigidity of the camera body 11 is high, the camera body 11 is not substantially deformed by a water pressure of about several atmospheres to several tens of atmospheres. On the other hand, since the display window 13 has very low rigidity, it is greatly deformed and bent to the inner surface side even at a pressure of about several atmospheres. When the display window 13 bends to the inner surface side, a pressure corresponding to the force applied to the display window 13 is applied to the pressure sensor 20 provided so as to be in contact with the display window and fixed to the mounting portion 30. . Thereby, the pressure sensor 20 can detect the pressure applied to the display window 13, that is, the pressure applied to the digital camera 10.

  In the present embodiment, the distance between the pressure sensor 20 and the display window 13 is shorter than the distance between the liquid crystal display 14 and the display window 13. Therefore, even if the display window 13 is bent and the pressure sensor 20 is pressurized by the display window 13, the display window 13 does not come into contact with the liquid crystal display 14, so the liquid crystal display 14 is pressed by the water pressure, and the liquid crystal display 14 The image quality of the image will not be lowered.

  FIG. 4 shows an electrical configuration of the digital camera 10 of the present embodiment. In the digital camera 10, a CCD (imaging device) 40 is provided behind the optical axis of the imaging optical system 42. The image sensor 40 is controlled by the CPU 41. The image captured by the imaging optical system 42 is displayed as a moving image or a still image on the liquid crystal display (LCD) 14 under the control of the CPU 41, and the still image is recorded on the memory card 47.

  A switch circuit 48 is connected to the CPU 41, and a signal is input from the switch circuit 48 to the CPU 41 when buttons provided on the back surface, top surface (see FIG. 1) of the camera body 11 of the digital camera are pressed.

  In the digital camera 10, when the release button 24 (see FIG. 1) is fully pressed, a release signal or the like is input from the switch circuit 48, the image sensor 40 is exposed, and shooting is performed. That is, when the release button 24 is pressed, exposure control or the like is performed, and the subject image captured by the imaging optical system 42 is converted into an image signal by the imaging device 40. The image signal is input to the CPU 41 and temporarily stored in the RAM 49. The image signal stored in the RAM 49 is read out again into the CPU 41, subjected to image processing by the CPU 41, and then recorded on the memory card 47 as a still image.

  The pressure sensor 20 is connected to the CPU 41, and the resistance value of each detection point is input from the pressure sensor 20 as needed, and the average pressure value that is the average value of the pressure values is calculated from the average value of the input resistance values. Is done. The calculated average pressure value is compared with a threshold value as will be described later, and if it is determined that the calculated average pressure value is equal to or greater than the threshold value, the pressure value is read together with the time read from the RTC (Real Time Clock) 52, etc. (Non-volatile memory) 51.

  FIG. 5 is a flowchart of an imaging routine according to the present embodiment. In step S100, when the power button 25 is input, the power of the digital camera 10 is turned on, and the operation of the digital camera 10 is started. In step S110, pressure detection is performed. That is, a plurality of pressure values are input to the CPU 41 from the pressure sensor 20, and the CPU 41 calculates an average pressure value. In step S120, it is determined whether the average pressure value is equal to or greater than a set threshold value.

  The threshold value is a value in the vicinity of the use limit pressure and a value that varies according to the routine operation. Here, the minimum value is, for example, a pressure value 0.8P that is 0.8 times the use limit pressure P, and the maximum value is the same value as the use limit pressure, and is set to the minimum value in the initial state. Is done. If the average pressure value is smaller than the threshold value in step S120, it is determined that the digital camera 10 is being used under normal conditions, and the process proceeds to step S130, where a normal photographing operation can be performed.

  On the other hand, if it is determined in step S120 that the threshold is equal to or greater than the threshold value, the condition in which the digital camera 10 is currently used is determined to be a use condition close to the use limit pressure, and a warning or the like is issued in step S200 and the following steps. It is further determined whether or not the operation of the digital camera 10 should be forcibly terminated.

  That is, in the present embodiment, when the average pressure value becomes equal to or greater than the threshold value, the average pressure value and the date and time when the pressure is measured are stored in the flash memory 51 in step S200, and a warning is issued in step S240. Here, the warning displays on the liquid crystal display 14 that, for example, the water depth currently used is too deep. In step S210 between step S200 and step S240, it is determined whether or not the number of times the threshold value has been increased is a predetermined number n. However, in the initial state, the predetermined number n is 0. The process proceeds to step S240 without proceeding to step S230.

  Further, after the warning is issued, the threshold value is increased in step S250. Here, the increase in the threshold is, for example, 0.01 times the use limit pressure (0.01 P). Therefore, in the initial state, when it is determined that the average pressure value is equal to or greater than the threshold value, in step S250, the threshold value is changed from 0.8P to 0.81P, and the process returns to step S110. In step S110, the average pressure value is detected again, and in step S120, the average pressure value is compared with the threshold value 0.81P. Even after the threshold value is raised, the same routine is repeated if the average pressure value is equal to or greater than the threshold value in step S120. In step S250, the threshold value continues to rise every 0.01P and a warning is also issued. However, for example, if the user changes the use conditions of the digital camera 10 in response to the warning and the pressure applied to the digital camera 10 becomes small, the average pressure value becomes smaller than the threshold value. It becomes possible. Also, when the average pressure value is equal to or greater than the minimum threshold value and smaller than the maximum threshold value, a warning is issued, but the process proceeds to step S130 after the threshold value has been raised several times, so that photographing is possible. .

  However, when the same routine is repeated, the threshold value gradually increases every 0.01P in step S250, and when the threshold value is increased a predetermined number of times n (20 times in the present embodiment), the threshold value becomes the use limit pressure (maximum Value). Here, when the threshold value becomes equal to the use limit pressure, the digital camera 10 is used in the vicinity of the use limit pressure for a long time (for example, several seconds). If the average pressure value is determined to be greater than or equal to the threshold value in step S120 when the threshold value is the highest value, the digital camera 10 is being used at a pressure equal to or greater than the use limit pressure. In such a case, the use of the digital camera 10 should not be continued.

  Therefore, in the present embodiment, in step S210, the number of times that the threshold value has been continuously increased is determined as described above, and when the number reaches the predetermined number n (20 times in the present embodiment), The process proceeds to step S230. In step S230, the last photographed image is read from the memory card 47, the image is recorded in the flash memory 51, and the power is forcibly turned off in step S300. The image recorded in the flash memory 51 is recorded in association with the pressure value recorded in step S200. Therefore, this image can be used as a reference for the photographing situation when the pressure is recorded.

  On the other hand, if it is determined in step S120 that the average pressure value is smaller than the threshold value, a normal photographing operation is performed in step S130 and the subsequent steps. That is, in step S130, it is determined whether or not the release button 24 is pressed. If it is determined that the release button 24 is pressed, the image sensor 40 is exposed in step S140, and a still image is obtained. In step S150, the obtained still image is recorded on the memory card 47. In step S160, it is determined whether or not the power button 25 has been pressed. If the power button 25 has been pressed, the process proceeds to step S300, where the power is turned off. On the other hand, if the power button 25 has not been pressed, the process returns to step S110 and this routine is repeated.

  Note that once it is determined that the average pressure value is equal to or less than the threshold value and the process proceeds to step S130, the predetermined number n and the threshold value described above are returned to the initial state. That is, the predetermined number n changed in the routine is stored in, for example, the CPU 41. However, once it is determined in step S120 that the average pressure value is equal to or less than the threshold value and the process proceeds to step S130, the number is cleared to zero. The Similarly, the threshold value is stored in the CPU 41, but once the process proceeds to step S130, the threshold value is returned to the initial value (minimum value). As a result, in this routine, the power supply is forcibly terminated only when the average pressure value is continuously n times or more than the threshold value.

  If it is determined in step S120 that the pressure value is greater than or equal to the threshold value, and if it is determined in step S210 that the predetermined number of times is 1, whether or not the pressure value is greater than or equal to the use limit pressure is determined in step S210. If the pressure value is equal to or higher than the use limit pressure, the process may proceed to step S230 to forcibly terminate.

  As described above, in the present embodiment, since the pressure (water pressure) can be detected with a simple configuration, the pressure (water pressure) at which the digital camera is used can be easily recognized. When the detected pressure value is higher than the threshold value, the pressure value and the date and time when the pressure value was detected are recorded in the nonvolatile memory. The situation at the time of failure can be confirmed, and the cause of the failure can be easily identified. Furthermore, since the warning is issued when the measured pressure (water pressure) approaches the use limit pressure, the user can be easily informed of the use status.

  In the present embodiment, only one pressure sensor 20 is provided on the upper side of the liquid crystal display 14 (see FIG. 1). However, for example, two pressure sensors 20 may be provided on the upper and lower sides of the liquid crystal display 14. good.

  The pressure sensor 20 of the present embodiment detects pressure even when pressed by a finger, for example. Therefore, when the pressure sensor 20 detects the pressure by pressing the finger and the detected pressure becomes, for example, the use limit pressure or more, the operation of the digital camera 10 is stopped. However, for example, when the display window is pressed by a finger, the pressing is local, and the two pressure sensors do not detect the same pressure at the same time.

  On the other hand, when the pressure is applied by the water pressure, the pressure detected by the two pressure sensors is substantially the same. For example, when the digital camera 10 is used under a water pressure equal to or higher than the use limit pressure, the pressure is detected by the two pressure sensors. The pressure values to be used are all equal to or higher than the use limit pressure.

  Therefore, when two pressure sensors are provided, for example, a warning is issued only when any of the pressure values detected by these pressure sensors is equal to or higher than the threshold pressure, and only when both are equal to or higher than the use limit pressure. The operation of the digital camera 10 may be stopped. In this case, a warning may be issued or the operation may be stopped only when the values of the two pressure sensors are the same (or the two pressure differences are within a certain range).

It is a rear view of the digital camera which concerns on embodiment of this invention. It is sectional drawing on the II-II line in FIG. It is sectional drawing on the III-III line in FIG. It is a block diagram which shows the electric constitution of a digital camera. It is a flowchart of the imaging | photography routine in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 11 Camera body 13 Display window 13a Visible part 13b Shielding part 14 Liquid crystal display 20 Pressure sensor 30 Mounting part

Claims (8)

  In a digital camera having a waterproof structure, a camera body, a liquid crystal display disposed on one surface of the camera body, a display window that covers the surface of the liquid crystal display and has lower rigidity than the camera body, and an inner surface of the display window On the side, a digital camera comprising a pressure sensor facing the display window and capable of detecting a pressure applied to the display window.   The digital camera according to claim 1, wherein a distance between the pressure sensor and the display window is shorter than a distance between the liquid crystal display and the pressure sensor.   The digital camera according to claim 2, wherein the pressure sensor is in contact with the display window.   The camera body is formed integrally with the camera body and has a mounting portion provided to face the inner surface of the display window, and the pressure sensor is mounted on the mounting portion. The digital camera according to claim 1.   The display window includes a transparent portion that transmits visible light and a shielding portion that blocks visible light, and the liquid crystal display is provided to face the visible portion, and the pressure sensor includes the shielding portion. The digital camera according to claim 1, wherein the digital camera is provided so as to face the camera.   The digital camera according to claim 1, further comprising a stopping unit that stops the operation of the digital camera when the pressure becomes a use limit pressure or more.   The digital camera according to claim 6, further comprising a nonvolatile memory that records a value of the pressure when the pressure is equal to or higher than a threshold pressure set to be equal to or lower than the use limit pressure. When the pressure is equal to or higher than a threshold pressure set to be equal to or lower than the use limit pressure, the pressure sensor further includes warning means for issuing a warning and gradually increasing the threshold pressure, and the stop means has the threshold pressure set to the use limit pressure. The digital camera according to claim 6, wherein when the pressure reaches or exceeds the threshold pressure, the operation of the digital camera is stopped.

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