JP4549465B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera supplied with energy by a secondary battery.
[0002]
[Prior art]
Several methods have been considered as a method for charging a secondary battery, and one of them is a method for charging a secondary battery by converting light such as the sun into a current by the solar battery. .
[0003]
In order to charge a secondary battery efficiently using a solar cell, the light receiving surface of the solar cell needs to be correctly directed to the sunlight, so the amount of light incident on the solar cell is detected and displayed. An apparatus is proposed in Japanese Utility Model Laid-Open No. 64-47183.
[0004]
Furthermore, the amount of charge of the secondary battery by solar charging greatly depends on how long the charging time is taken. Even when the sunlight is strong and the amount of output current is large, if sufficient charging time is not taken, the desired energy cannot be obtained. For example, when a camera is considered as a device that operates with such a secondary battery. There is a risk that sufficient shooting cannot be performed. On the other hand, if the battery is charged for a long time even with a small amount of light, photographing can be performed.
[0005]
[Problems to be solved by the invention]
In other words, in a device such as a camera, it is desirable that the amount of charge is displayed with a content that can be accurately grasped by the user during solar charging .
[0007]
The present invention has been made in view of the above points, and it is an object of the present invention to provide a camera that allows a user to accurately grasp the amount of charge due to solar charging and enjoy efficient charging and many shootings. And
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a camera according to the present invention is a camera provided with a solar battery for charging a rechargeable battery,
A display unit for displaying the amount of charge by the solar cell;
A display control unit for controlling the display unit;
Comprising
The display control unit displays, as the charge amount display, an integrated display converted into a shootable number of images corresponding to an integrated signal detected and integrated at a predetermined time interval for a signal corresponding to the amount of light incident on the solar cell. when performing, the number of possible shots depending on whether is at least one, and controls the starting and stopping of the charging amount of the display operation in the display unit.
[0009]
That is, according to the camera of the present invention, the amount of charge to the rechargeable battery is detected, and the detected amount of charge is integrated and converted into the number of images that can be shot. Since the display is started and stopped depending on whether or not, the user can accurately grasp the amount of charge by solar charging.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
(First embodiment)
A first embodiment as a concept of the present invention will be described with reference to FIG.
[0016]
That is, FIG. 1A is a block diagram of the camera according to the first embodiment of the present invention, and is a one-chip that controls the sequence of the entire system including the photographing function 7 (shutter, lens drive, etc.). An arithmetic control means (CPU) 1 comprising a microcomputer or the like controls the photographing function 7 and the display unit 2 according to the change of the switch 6 operated by the user. The switch 6 may be a specially provided switch, or may be one that responds to shutter release or opening / closing of a lens barrier.
[0017]
As the energy of such a circuit, the energy stored in the secondary battery 5 is used. The secondary battery 5 is charged with energy obtained by converting solar light into current by the solar battery 3. This charge amount is detected by the charge amount monitor unit 4 and input to the CPU 1.
[0018]
Note that reference numeral 1a in the figure is an EEPROM that stores energy for one shooting of this camera, and stores the energy consumption at the time of shooting that changes for each unit due to component variations and the like. .
[0019]
Reference numeral 1b is a temperature sensor. That is, since the hardness of the film changes depending on the temperature, the energy consumption required for photographing changes. In order to take this into consideration, the ambient temperature is measured by the temperature sensor 1b, and the temperature measurement information is input to the CPU 1.
[0020]
The camera having such a configuration operates as shown in the flowchart of FIG.
[0021]
That is, when the user turns on the switch 6 (step S1), the CPU 1 takes in the charging current I monitored by the charge amount monitoring unit 4 (step S2), and the elapsed time from the timing when the switch 6 is turned on. t is counted (step S3). Then, assuming that the charging current of I has flowed for t time, the amount of charge is calculated by performing the calculation of I × t (step S4).
[0022]
On the other hand, as described above, the current consumption at the time of shooting varies depending on the environmental temperature and the variation in the quality of the camera. Therefore, the CPU 1 takes in the environmental temperature T measured by the temperature sensor 1b (step S5). The camera variation data recorded in advance at the factory is read from the EEPROM 1a (step S6).
[0023]
Then, in consideration of the variation with these environmental temperature T, CPU 1 is determined by calculating the energy required to single shooting becomes _{I s} × _{t s} (step S7). Here, I _s is the current consumed by the release operation once in consideration of the temperature and variation, t _s is the time consumed. Note that a conversion table between temperature and energy may be provided as data of the EEPROM 1a.
[0024]
Thus, since the integrated value of the charged energy and the energy consumption under the environment at that time can be determined by the CPU 1, the CPU 1 converts the number of shots from these data and displays it on the display unit 2. Display (step S8). Then, the process returns to step S1.
[0025]
By going through the loop of steps S1 to S8, the charging energy is sequentially accumulated in step S7, and the display is updated.
[0026]
Therefore, as shown in FIG. 2A, the user 20 determines whether the camera unit 14 is placed in the car window, for example, when going on a trip, so that solar charging is performed, and the display unit 2 determines how many pictures can be taken. can do. The display on the display unit 2 at this time is as shown in FIG. 2B, and reference numeral 2b in the drawing is a display during solar charging. Reference numeral 2a is a shootable number display portion in which the charge amount is converted into the number of shootable frames, and is shown here as a bar graph.
[0027]
As described above, according to the first embodiment, an easy-to-understand charge display is possible in consideration of the camera performance and the environmental temperature.
[0028]
(Second Embodiment)
Next, a second embodiment of the present invention will be described. The second embodiment is a camera that allows not only solar cells but also AC charging.
[0029]
FIG. 3 is a diagram showing a circuit configuration of a camera according to the second embodiment of the present invention.
The portion related to solar charging is basically the same configuration as the camera according to the first embodiment shown in FIG. 1A, but in this figure, the charge amount monitor from the solar cell 3 is shown. Part 4 is shown in more detail.
[0030]
That is, since the DC / DC converter 8 can boost the voltage to a level higher than that of the secondary battery 5, the A / D converter 4b converts the charging current from the solar battery 3 into a voltage by the resistor 4a. it is possible to monitor the value V _1. The CPU 1 thereby determines the charging current. Further, reference numeral 10 is a backflow prevention diode, and when the secondary battery 5 is fully charged by the AC charger 12, solar charging is unnecessary, and battery deterioration due to overcharging occurs. The CPU 1 turns on the switch transistor 11 so that a solar charging current flows through the collector of the transistor. The voltage of the secondary battery 5 is supplied to the photographing function 7 such as the CPU 1, the shutter 7 a, the focusing mechanism 7 b, the photometry / ranging (AE / AF) unit 7 c through the filter 9.
[0031]
The display unit 2 and the switch 6 are the same as those in the first embodiment.
[0032]
FIG. 2C is a diagram showing the appearance of the camera 14. That is, in addition to the solar cell 3 and the strobe light emitting unit 17, a barrier 15 for protecting the lens is provided on the front surface of the camera. On the top surface, a release SW 18a, other switches 18b, and the like are provided. If the camera 14 is placed on the AC charger 12, the electric energy that enters from the outlet 13 is converted into magnetic energy, and the camera It is input to a secondary coil (not shown) in the inside and returned to electrical energy in the camera to charge the secondary battery.
[0033]
At the time of shooting, when the barrier 15 is opened, as shown in FIG. 2D, the protected shooting lens 16 comes out, and the distance measurement / photometry window 19 appears.
[0034]
In addition, the display unit 2 is provided on the back surface of the camera 14 as shown in FIG.
[0035]
4A and 5A show a series of operation flowcharts of the camera according to the second embodiment.
[0036]
That is, the CPU 1 first determines whether the barrier 15 is open or closed according to the state of a barrier switch (not shown) that is turned ON / OFF according to the opening / closing of the barrier 15 (step S10). Here, if the barrier 15 is open, it will be in imaging | photography mode and a predetermined display will be performed on the display part 2 (step S11). If no shooting instruction such as operation of the release SW 18a is given (step S12), the process returns to step S10.
[0037]
On the other hand, if it is determined in step S10 that the barrier 15 is closed, the charging mode is set. That is, in this example, a barrier switch (not shown) that is turned ON / OFF according to opening / closing of the barrier 15 is used as the switch 6. Note that, in the photographing mode, the display unit 2 is always in the display ON state. In the charging mode, ON / OFF of the display unit 2 is switched depending on whether or not it is charged. That is, energy is required for display, and if the display is turned on even though it is not charged, useless energy consumption occurs.
[0038]
Thus, when the barrier is closed, the CPU 1 first resets both the register E holding the charge energy amount and the register M holding the number of shootable images to “0” (step S13). And it is judged whether AC charge is carried out (step S14). During AC charging, the display unit 2 is turned on to indicate that AC charging is to be performed (step S15), and it is determined whether charging has been completed (step S16). If charging has not been completed, the process returns to step S10. When the charging is completed, an end display is displayed on the display unit 2 (step S17), a completion flag is set (step S18), and the process returns to step S10.
[0039]
On the other hand, if it is determined in step S14 that the charging is not AC, the CPU 1 next determines whether or not a completion flag is set (step S19). If the completion flag is set, the switch transistor 11 is turned on to prohibit solar charging in order to prevent overcharging of the battery (step S20). Then, the display unit 2 is turned off (step S21), and the process returns to step S10.
[0040]
On the other hand, when the completion flag is not set, it is determined whether or not the mode for performing solar charging is set (step S22). When the mode is not set, step S21 is performed. Then, the display is turned off.
[0041]
When the mode for performing solar charging is set, the CPU 1 calls a charge amount conversion subroutine, which will be described later in detail (step S23), and each time the subroutine is called, the charge amount E during that time is called. ₁ is required. And the value of the register | resistor E holding a charge energy amount is updated by adding the calculated | required charge amount (step S24). Thereafter, a subroutine for displaying the number of shootable images, which will be described later in detail, is called (step S25), the number of shots is obtained (the calculated number of shots is held in the register M), and displayed on the display unit 2 (step S25). ). At this time, if the amount of solar charge is not large (step S26), the process returns to step S10. If the amount of solar charge is large, the display is blinked (step S27), and then the process returns to step S10.
[0042]
On the other hand, when it is determined in step S12 that the photographing operation has been performed with the barrier open, a battery check (BC) subroutine (to be described later in detail) is called (step S28), and the battery check is performed. Thereafter, a known photographing operation is performed (step S29). If shooting is performed in this manner, it is natural that there is also current consumption. If the charge completion flag is set (step S30), it is cleared (step S31). Further, if the number of shots held in the register M is smaller than “1” (step S32), the process returns to step S10, and if larger than “1”, the value of the register M is decremented. (Step S33), the process returns to Step S10. Accordingly, since the value of the register M is displayed in the above step S11, the display in which the charge amount is converted into the number of shots is decremented every time shooting is performed.
[0043]
FIG. 5B is a flowchart of the battery check (BC) subroutine called in step S28.
[0044]
That is, first, the battery voltage is monitored (step S281), and it is determined whether or not the voltage is sufficient (step S282). If the voltage is sufficient, the battery mark 2d as shown in FIG. 2E is displayed on the display unit 2 (step S283), and the process returns to the upper routine. When the battery voltage is low, it is determined whether or not the value can be compensated by solar charging (step S284), and if it can be compensated by solar charging, the process returns to the upper routine without performing anything. If this cannot be compensated, a message to that effect is displayed on the display unit 2 (step S285), and the process returns to the upper routine. The AC charging warning display in step S285 is emphasized by, for example, blinking the “AC” display 2e as shown in FIG.
[0045]
Further, the charge amount conversion subroutine called in step S23 is as shown in the flowchart of FIG.
[0046]
That is, first, the voltage V ₁ across the resistor 4a of the charge amount monitor unit 4 is monitored (step S231). If this is “0” (step S232), the charge amount E ₁ is determined because charging has not been performed. “0” is set (step S233), a display unnecessary flag is set (step S234), and the process returns to the upper routine.
[0047]
On the contrary, when the voltage across _{V 1} of the resistor 4a in step S232 is determined not "0", then, by turning ON the DC / DC converter 8 as described previously (step S235), by increasing the detectable range of the a / D converter 4b, again, the voltage across _{V 1} of the resistor 4a monitor to it and _{V 11} (step S236). Then, after resetting the counter t for counting the elapsed time to "0" (step S237), counts the elapsed time (step S238), if the time predetermined _{t 1} has elapsed (step S239) again, by monitoring the voltage across _{V 1} of the above resistance 4a, that it with _{V 12} (step S23A). Then, the amount of current is obtained from the average value ((V ₁₁ + V ₁₂ ) / 2) of V ₁₁ and V ₁₂ , and the amount of charge E ₁ is obtained by multiplying by the time t ₂ of the period when this subroutine is called (step) S23B). Thereafter, the DC / DC converter 8 is turned off (step S23C), and the process returns to the upper routine.
[0048]
Further, the shootable image number display subroutine called in step S25 is performed as shown in FIG.
[0049]
That is, first, it is determined whether or not the above-described display unnecessary flag is set (step S251). If the flag is set, the display unit 2 is controlled to be turned off (step S252). Return to the routine.
[0050]
On the other hand, when the display unnecessary flag is not set, that is, when the charging current is large, the value E obtained by integrating the charge amount E ₁ obtained in step S2 3 B of the charge amount conversion subroutine in step S24. but it calculates how equivalent to many times the one of the current consumed by the release operation _{I s} and the product of the time spent _{t s (I s × t s} ) ( step S253).
[0051]
If the calculation result M is less than one (step S254), the process proceeds to step S252, the segment display is not performed, the display unit 2 is controlled to be turned off, and the process returns to the upper routine. .
[0052]
However, if the calculation result M is one or more, it is next determined whether or not it is less than two (step S255). If so, one segment of the display unit 2 is turned on. (Step S256), the process returns to the upper routine. If the number is two or more, it is next determined whether or not the number is less than three (step S257). If so, two segments of the display unit 2 are turned on (step S258). If there are three or more, three segments of the display unit 2 are turned on (step S259), and the process returns to the upper routine.
[0053]
That is, as shown in FIG. 2E, the display unit 2 includes a shootable number display unit 2a including three segments, and these three segments are selected according to the shootable number (calculation result M). Is controlled to light up. In FIG. 2E, reference numeral 2c indicates the number of frames that have already been shot.
[0054]
Also, here is a simplified example where segment display is not performed when charging less than one image. To know how long it takes to charge for one image, the segment for one image is displayed. For example, as shown in FIG. 2 (F), the user waits for charging by dividing into a plurality of parts and showing charging as 1/5, 2/5, 3/5,... It is preferable as a measure of time. At this time, the blink frequency may be finely changed according to the magnitude of the charging current.
[0055]
As described above, according to the second embodiment, the user can easily recognize and recognize whether AC charging is good or solar charging, and prevent unnecessary overcharging during solar charging. Thus, it is possible to take measures against battery deterioration and make the user recognize the charging effect in an easy-to-understand manner so that the time to wait for charging can be known in advance.
[0056]
Although the present invention has been described based on the above embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the gist of the present invention.
[0057]
Here, the gist of the present invention is summarized as follows, in addition to those described in the claims.
[0058]
(1) The camera according to claim 1, wherein the switch means is a barrier means that protects the front surface of the photographing lens of the camera, or a switch that works in conjunction with a release means that is operated during photographing.
[0059]
(2) The camera according to claim 1, wherein the charge amount detection means periodically monitors the charge state, and detects the charge amount according to the charge state and an elapsed time from the switch timing. .
[0060]
(3) In a camera with a built-in rechargeable battery having two series of charging means,
A camera comprising: prohibiting means for prohibiting the charging operation of the other charging means when it is detected that the one charging means is fully charged.
[0061]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to allow the user to accurately check the amount of charge due to solar charging, thereby allowing the user to take sufficient solar charging time and efficiently. A camera that can be charged and enjoyed many shootings can be provided.
[0062]
In addition, since the user can check the amount of charge by solar charging, the user can take a picture while sandwiching the charging as appropriate according to the display, and can use the battery energy for a long time.
[Brief description of the drawings]
FIG. 1A is a block diagram of a camera according to a first embodiment of the present invention, and FIG. 1B is a diagram showing an operation flowchart of the camera according to the first embodiment.
FIGS. 2A and 2B are diagrams illustrating a state where solar charging is performed, FIG. 2B is a diagram illustrating a display example of the display unit of the camera according to the first embodiment, and FIGS. The figure which shows the external appearance when the barrier of the camera which concerns on 2nd Embodiment is closed, respectively, respectively, (E) is a figure which shows the example of a display of the display part of the camera which concerns on 2nd Embodiment. (F) is a figure which shows another example of a display of the display part of the camera which concerns on 2nd Embodiment.
FIG. 3 is a diagram showing a circuit configuration of a camera according to a second embodiment of the present invention.
FIG. 4 is a diagram showing the first half of a series of operation flowcharts for explaining the operation of the camera according to the second embodiment.
5A is a diagram showing a second half of a series of operation flowcharts for explaining the operation of the camera according to the second embodiment, and FIG. 5B is a flowchart showing a battery check (BC) subroutine. (C) is a diagram showing a flowchart of a shootable number display subroutine.
FIG. 6 is a flowchart of a charge amount conversion subroutine.
[Explanation of symbols]
1. Arithmetic control means (CPU)
1a EEPROM
1b Temperature sensor 2 Display unit 2a Number of shootable images display unit 2b Display during solar charge 2d Battery mark 2e “AC” display 3 Solar cell 4 Charge amount monitor unit 4a Resistance 4b A / D converter 5 Secondary battery 6 Switch 7 Shooting function 8 DC / DC converter 9 Filter 10 Diode 11 Switch transistor 12 AC charger 14 Camera 15 Barrier 18a Release SW
20 users

Claims (1)

In a camera provided with a solar battery for charging a rechargeable battery,
A display unit for displaying the amount of charge by the solar cell;
A display control unit for controlling the display unit;
Comprising
The display control unit displays, as the charge amount display, an integrated display converted into a shootable number of images corresponding to an integrated signal detected and integrated at a predetermined time interval for a signal corresponding to the amount of light incident on the solar cell. when performing a camera, characterized in that the number of possible shots depending on whether is at least one, controls the start and stop of the charging amount of the display operation in the display unit.

Images