JPS58132737A - Display of exposure controlling value - Google Patents

Abstract

PURPOSE:To simplify recognition, and also to decide at a glance the remaining quantity of a battery or a replacement time, namely, a life, by constituting a titled display so that voltage is displayed on a dot display part in case when the voltage of an power supply battery is prescribed voltage or above, and an alarm such as flashing, etc. is given in case when it is below prescribed voltage. CONSTITUTION:An output of a photometric circuit 1 and an output of a power supply battery circuit 2 are selectively switched by a switching circuit 3, an analog signal from the switching circuit 3 is converted to a digital signal VAD by an A/D converting circuit 4 and is applied to a central processong unit 5, and digital operation is executed so that the digital signal VAD is suitable for display. A display 6 containing a digital display part 6a and a dot display part 6b is displayed as shown in a figure (a) at the time of photometry, and is displayed as shown in a figure (c) at the time of battery check. In this way, by utilizing a digital operating circuit of a digital exposure value controller, and the display 6, the voltage of a power supply battery is displayed in bar graph, displayed in dot or digitally displayed, and in case when it is prescribed voltage or below, it is alarmed by flashing, etc. Therefore, in case when the voltage of the power supply battery is prescribed voltage or above, a digital operation result can be displayed almost analogously by the bar graph display or the dot display, and in case when it is prescirbed voltage or blow, an alarm can be executed by flashing, etc., therefore, the recognition is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure control value display device for a light meter, a camera, etc.

Conventionally, for example, when checking the battery of a digital display light meter, when the voltage of the power source battery falls below a specified voltage, a warning is given by flashing or other means on the display device. However, it is impossible to predict when the battery will run out during use.
I always had to carry spare batteries.

In view of the above points, the present invention focuses on the fact that a manganese battery causes a voltage drop due to discharge as shown in FIG. We would like to provide an exposure control value display device that allows you to know the remaining battery power and the time to replace the battery from the displayed voltage. To explain this using an embodiment, FIG. 2 is a block diagram showing the circuit of this embodiment, in which 1 is a photometric circuit, 2 is a power supply battery that outputs an analog signal corresponding to the voltage VB of a manganese battery for power supply. 3 is a switching circuit that can selectively switch between the output of the photometric circuit 1 and the output of the power supply battery circuit 2; 4 is an A/D conversion circuit that converts the analog signal from the switching circuit 3 into a digital signal; 5 is an A/D conversion circuit; A central processing unit performs digital calculations to make the digital signal frame suitable for display, and 6 is a display device including a digital display section 6a and a dot display section 6b.
When checking the battery, for example, as shown in Figure 3 (C
) etc. are displayed.

The embodiment of the present invention is constructed as described above, and the operation when performing a pantry check is controlled by the central processing unit 5 as shown in FIG. That is, after all the display parts of the display device 6 are turned off by the start command, Jb and cJ are displayed on the digital display part 6a of the display device 6 (see FIG. 3(b)), and the switching circuit 3 is turned off. The power source is switched to battery circuit 2. Preferably, the switching circuit 3 is configured so that after being switched to the power source battery circuit 2, the switching circuit 3 is automatically switched back to the photometry circuit 1 after a certain period of time has elapsed. Thus, A/D conversion is performed in the A/D conversion circuit 4 under the control of the central processing unit 5, and vAD
A signal is output. Here, as shown in FIG. 5, the signal vAD is, for example, a battery voltage 1. It has a first-order proportional relationship with the battery voltage VB, which should be "100" with respect to OV (specified voltage). Next, the calculation Y-vAD-ioo is performed and y
<o, that is, when the battery voltage VB < 1 and OV tv, the display "b, c" is on for 0.5 seconds and then all displays are off for 0.5 seconds, which is repeated, so-called flashing is performed, and the power is turned off. Check that the battery voltage vB has not reached 1.0■. In particular, if V3<0.7 V, the entire device will not operate and therefore no display will occur.

Also, when Y2O, that is, when the battery voltage 9 is 1.07 or more, x-Yx4 is calculated, followed by Y'=X÷10, which is 0, and then X'=Y'+1, X'-
((vAD-100) and the fourth tooth C).In this case, as shown in FIG. 4B, from the left of the dot display section 6b
Dot display may be performed by turning on only the 'th dot (see Fig. 3(d) and the fourth tooth C).
. In addition, the above bar graph display or dot display
Alternatively, at the same time as these displays, as shown in FIG.
The battery voltage VB may be digitally displayed by turning on the decimal point of the voltage display segment of the digital display section 6a of No. 6 and displaying the above 2 on this display segment (see #g3 (θ) and the 4th tooth). (See C). The battery check operation is completed with the display as described above, but if the switching circuit 3 is automatically returned to the photometry circuit 1 as described above, the state is then switched to the photometry state.

Incidentally, the relationship between the battery voltage VB, the digital calculation power 'AD9 calculation results Y' and X', and each display is as shown in the table of FIG. Also, the dot display is 0.0 per piece.
For example, when seven dots are displayed, the actual battery voltage VB is 1.15V≦VB<1.175V.

As described above, according to the present invention, the voltage of the power supply battery is displayed as a bar graph, dot display, or digitally using the digital calculation circuit and display device of the digital exposure value control device, and when the voltage is below the specified voltage, Since the system is designed to issue a warning by flashing, etc., when the voltage of the power supply battery is above the specified voltage, the digital calculation result can be displayed in a roughly analog manner with a bar graph display or dot display, and when the voltage is below the specified voltage, the digital calculation result can be displayed in a roughly analog manner. Since a warning can be given by flashing or the like, it is extremely easy to recognize, and has the effect of immediately cutting off the remaining amount of the battery or the time for replacement, that is, the life span.

In addition to the warning by flashing, other warning means such as a warning sound by a buzzer or the like are also possible.

Furthermore, it goes without saying that the present invention can be applied to cameras incorporating a photometry mechanism, an automatic exposure mechanism, and the like.

[Brief explanation of the drawing]

Fig. 1 is a discharge curve diagram of a manganese battery, Fig. 1 is a block circuit diagram of an exposure control value display device according to the present invention, and Fig. 3 is a diagram showing an example of the display device, in which (a) is during photometry, (b) is a diagram showing an example of the display device. is when the battery check operation starts. (C+ shows the display performed in the case of bar graph display, (d) in the case of dot display, and (e) in the case of digital display. Fig. 4 is a flowchart of the pantry check operation by the central processing unit. , Figure 5 shows the battery voltage V
B is a table showing the relationship between the digital output vAD, the calculation results Y' and X', and each display. 1. Photometering circuit, 2... Power supply battery circuit, 3... Switching circuit, 4... A/D conversion circuit, 5... Central processing unit, 6... Display device. Figure 1 Figure 2 Procedural amendment (method) 1. Case display patent application No. 57-15979 Publication number λ Name of the invention Exposure control value display device 3, person making the amendment Patent applicant Sekonic Co., Ltd. 5, 558 Oizumi Gakuencho, Nerima-ku, Tokyo Date of amendment order 1982 May 25, 6, column for detailed description of the invention and column for brief description of drawings of the specification to be amended. 7. Contents of amendment (1) Lines 4 to 5 of page 6 of the specification letter are corrected to read "Table J in Figure 5 r Figure 5." (2) This is Table 1 on page 7, line 17 of the detailed letter. "of"
This is a diagram. ” he corrected.

Claims (5)

[Claims] (1) A switching circuit that can selectively switch between the output corresponding to field brightness information from the photometry circuit and the output corresponding to the voltage of the power supply battery, and an A/D that converts the output of the switching circuit into a digital signal. The display device includes a conversion circuit, a central processing unit that performs digital calculations to make a digital signal based on the voltage of the power battery suitable for display, and a display device having a dot display section, and the display device has a dot display section, An exposure control value display device, characterized in that when the voltage is lower than the specified voltage, the voltage is displayed on a dot display section, and when the voltage is lower than the specified voltage, a warning such as flashing is given. (2) Claim (1) characterized in that the A/D conversion circuit is controlled by a central processing unit.
).The exposure control value display device described in ). (3) The exposure control value display device according to claim (1) or (2), wherein the display made on the dot display section is a pergraph display. (4) Claim (1) or (2) characterized in that the display made in the dot display section is a dot display.
).The exposure control value display device described in ). (5) The exposure control value display device according to claim (3) or (4), characterized in that the voltage of the power source battery is digitally displayed.