JPH0358041A - Power control device for camera - Google Patents

Abstract

PURPOSE:To attain conditional detection and current control without wasteful power consumption by energizing the open side of the conditional switch exactly only at the time of changing. CONSTITUTION:While a rear lid is opened, a signal line 36 is not terminated by a rear lid switch SW34 possessing one circuit and two contact points, and therefore, the output of a inverter 140 is L. Consequently, the output of an AND gate 4 is L, the output of a NOR gate 39 remains at H, and power supply to a control unit 3 is stopped. When the rear lid is closed, the line 36 is L, the output of the 140 is H, the output of the gate 39 is L, and the power supply is started by a transistor 12: The unit 3 detects that the rear lid is closed and carrys out necessary control such as automatic paper feeding. Thus,necessary conditional detection and power control can be attained with a simple circuit without wastefully consuming power.

Description

DETAILED DESCRIPTION OF THE INVENTION (Background of the Invention) The present invention relates to a power control device for a camera, and in particular, the present invention relates to a power control device for a camera, and in particular, the device has two states (on and off) of a device that changes state depending on the user's actions, such as a back cover. This invention relates to the improvement of a power supply control device for a camera that is suitable for cameras that adopt the following two states and are likely to remain in the two states for a relatively long period of time. (Background of the Invention) Conventionally, the power supply of a camera is 1) powered only when the back cover is closed, 2) powered on by other means, and a microcomputer or the like intermittently checks whether the camera is opened or closed, or 3) checked for a predetermined period of time. However, there were some that turned on by other means.

Here, these conventional examples will be explained using figures.

FIG. 6 shows a simple example in which the power source 1 is configured to be supplied to the control unit 3 of the camera through the back cover switch 2 only when photographing, that is, when the back cover is closed.

In this case, the back cover serves as the power switch, so it is easy to understand and simple. However, there is a drawback that when the back cover is opened, operations and mode settings corresponding to the opening operation cannot be performed.

FIG. 7 shows another example in which the control unit 3 connects the signal line 7 to “
By setting it to "H", the signal line 8 for back cover detection is set to "H" through the buffer 6.The back cover switch 4 is configured to turn on when it is opened.Then, the signal line 8 is set to "H".
As long as the back cover is closed or opened, it can be detected by the "H" and "L" levels of the signal line 9.

Normally, the back cover is closed, so the back cover switch 4 is off. Therefore, this switch sense consumes almost no power. Then, when the back cover is open, switch 4 is turned on,
The signal line 9 becomes "L", and the signal passed through the buffer 10 causes the resistor 11 to be connected to the resistor 1 and the transistor 12.
is turned on to energize the control unit 3. This has the advantage that the control unit 3 can perform some work when the back cover is opened.

However, when the back cover is open, the power supply is left unused. For this reason, when the back cover is opened for a long time, the resistance
The current flowing through can no longer be ignored. Therefore, the control unit 3 has no choice but to turn the signal line 7 to "L" and give up on detecting the back cover state.

In this case, cut off the signal line l3, give up on detecting that the back cover is closed, and use a completely different operation switch to turn on the transistor 12 and turn on the power again (to enable work when the back cover is closed). must be done.

FIG. 8 shows another example in which the current flowing through the resistor 5 is unavoidable, and the current is applied to the control unit 3 only when the back cover changes to open or close. That is, when the signal line 9 falls or rises when opened or closed, the mono multivibrator 14 or 15 is started, and when the signal line 9 changes, the Q output is made to be "H" for a certain period of time, and then the signal is passed through the NOR gate 16 and the resistor 11 to the transistor 12. Turn it on.

As a result, except for the power consumption caused by the resistor 5 when the back cover is opened, the control unit 3 can be energized only when a change occurs, and the work corresponding to the change can be performed.

FIG. 9 shows an example in which the change detection shown in FIG. 8 is performed intermittently, in which the low frequency oscillator 17 supplies a clock to the D flip-flop 18, and the exclusive gate 19 detects the change. That is, the circuit is designed to turn on current when there is a change between clocks.

Figure l○ is an example using the so-called dynamic bull-up method. That is, this is an example in which the resistor 5 is intermittently energized by the low frequency oscillator 20 in order to suppress power consumption by the resistor 5. Changes are detected by the D flip-flop 18 and the exclusive gate 19 during the intermittent energization period.

As is clear from the above, conventional power supply control devices of this type require special circuits such as a means to monitor the switch for a predetermined period of time or intermittently, and also require a special circuit to keep the circuit working. They were forced to consume electricity.

(Object of the Invention) The object of the present invention is to solve the above-mentioned problems, and to perform necessary state detection and power control without wasting power consumption.
It is an object of the present invention to provide a power supply control device for a camera that can be configured with a simple circuit.

(Features of the Invention) In order to achieve the above object, the present invention provides a switch having two series: a switch part that is turned on in response to the back cover being open, and a switch part that is turned on in response to the back cover being closed. means and
Equipped with a power control means that detects the switch part that is turned on in response to each action of opening the back cover and starts the power supply, it can be easily configured and consumes no power. The present invention is characterized in that a switch means capable of detecting the state is adopted, and the start-up control of the power supply is performed.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which the control unit 3 uses a flip-flop 3l, a resistor 32.
33, selectively outputs "H". It is also assumed that the back cover switch 34, which has one circuit and two contacts, is turned on to the signal line 36 side when the back cover is closed.

When the control unit 3 thinks that the back cover is closed, it sets the flip-flop 3l to pull up the resistor 32. If the back cover is closed, the signal line 35 is an oven, so the input to the inverter 37 is "H" and its output is "
Then, the output of the AND gate 38 becomes "L", and the output of the NOR gate 39 becomes "H". This is a case where the state expected by the control unit 3 and the state of the back cover match.

Here, when the back cover is opened, the signal line 35 is “
The output of the inverter 37 becomes "H", the output of the AND gate 38 also becomes "H", and the output of the NOR gate 39 becomes "L".

This is a case where the control unit 3 misidentifies the state.

At the time of this erroneous recognition, the output of the NOR gate 39 becomes "L", so the transistor 12 is turned on, power is supplied to the control unit 3 through the resistor 11, and the control unit 3 is supplied with power, and the output of the NOR gate 39 becomes "L". “I learned about the misconception of the condition by something like that.

Based on this recognition, the control unit 3 resets the flip-flop 31 while confirming the power supply and identifies that the back cover is open. Here, the power supply can be cut off after performing the processing necessary to open the back cover (clearing the film counter and completing rewinding).

At this time (when the flip-flop 3l is reset), the resistor 32 is pulled down and, conversely, the resistor 33 is pulled up.

While the back cover is open, the signal line 36 is not terminated at the switch 34, so the output of the inverter 40 is 'L'.Therefore, the output of the AND gate 41 is 'L', and the output of the NOR gate 39 is 'L'. The voltage remains at "H", and the power supply to the control unit 3 is stopped.

If the back cover is closed, the signal line 36 is “L”.
”, the output of the inverter 40 becomes “H”, the output of the AND gate 41 becomes “H”, and the output of the NOR gate 39 becomes “L”, and power supply by the transistor 12 is started.

Thereby, the control unit 3 detects that the back cover is closed and performs necessary controls such as automatic feeding.

As explained above, the CMOS-IC is easy to monitor the switch by energizing the oven side of the status switch, waiting for a change without consuming current, and accurately energizing only when there is a change.
It can be achieved with

That is, compared to the conventional dynamic pull-up using an oscillator, switch detection with low impedance can be realized with minimal power consumption and with a simple logic element.

Of course, the back cover switch 34 has an additional contact point, but the switch structure only requires one additional contact piece as shown in FIG. 2, and is a simple change. In FIG. 2, 34a is a holding part, 34b is a common grounding terminal, 34c is a contact piece on the signal line 36 side that is turned on when closed, 34d is a contact piece on the signal line 35 side that is turned on when opened, and 43 is a protrusion integrated into the back cover that enters leftward as shown in the figure when the back cover is closed.

Incidentally, there is a known method for selectively supplying power to a switch having one circuit and two contacts. That is, as shown in FIG. 11, power control using a two-contact switch includes blinking a light 60 using three-way switches 61 and 62 in a commercial power source. However, this is not a switch detection as in the present invention, but the switch itself has power control capability.

That is, it does not perform logical switch detection and power supply control based on the logical switch detection as in the present invention.

By the way, the idea of this project is to use two switches that do not turn on twice (for long periods of time) and alternately turn them on, thereby almost eliminating static power consumption for status detection. FIG. 3 is another embodiment showing an example of performing the above operations using a patrone presence/absence switch.

The back cover 50 is made so that a cartridge 52 can be inserted into the main body 5l. Here, due to the presence of the cartridge 52, the protrusion 54, which is pivotally supported by the cartridge 53 and always biased counterclockwise, is rotated clockwise, and the switch 55 is turned on.

Incidentally, reference numeral 43 denotes a protrusion integrated into the above-mentioned back cover 50, which separates the contact pieces 44 and 46 when the back cover is closed, turning it off.

When the back cover is closed, the contact pieces 44 and 46 are off, and the cartridge 52 is closed.
is pushed to the left by the back cover pressure, turning on the switch 55 as shown in the figure. Conversely, when the back cover is open, the contact pieces 44 and 46 are on, and the cartridge 52 is not pressed against the back cover 50, so the protrusion 5
The village pressure of 4 pushes the player out of the patrone room, and the switch 55 turns off.

In this way, the switch 55 for detecting the presence or absence of a cartridge is connected to the switch contact piece (the contact piece 34 in FIG. 2) that is turned on when the back cover is opened.
It can be used instead of d).

In this case, if the back cover is open and the cartridge 52 is continued to be pushed in artificially, both switches will turn on, and current will be consumed by the switch detection resistor, but there is less chance of it being left as is than in the conventional case. Therefore, the power can be ignored.

FIG. 4 shows another embodiment in which the mechanical patrone presence/absence switch 55 of FIG. 3 is replaced with an electrical switch.

Currently, according to ISO standards, the cartridge 52 is provided with a contact pattern called DX code (see Figure 5).
It is used for automatic setting of film sensitivity, etc.

This pattern has two zones #1 for the common electrode.
#7 is configured, and sensitivity setting is normally performed using one of them and a part of the 5 zones #2 to #6 for sensitivity codes.

The contact pieces for this detection are 57 and 58 shown in Figure 4. In this embodiment, one contact piece (not shown) is added to common electrode zones #1 and #7, and this is used as a switch contact piece (contact piece 34d in Fig. 2) that is turned on when the back cover is opened. ) instead.

As a result, a switch that is turned on when the cartridge 52 is pushed in manually and when the back cover 50 is used can be formed by adding one contact piece.

According to this embodiment, for example, a switch having two contacts is used to logically activate a signal line in a state opposite to the recognized state, and the activation signal line is terminated due to a change in state. , the power supply is controlled in order to recognize changes in the state. This makes it possible to easily activate the control system in response to a change without consuming power (including power required for activation) when there is no change in state. In other words, by adding one switch contact and a simple logic gate, necessary state detection and power supply control can be realized with a simple circuit configuration without wasting power consumption.

(Effects of the Invention) As explained above, the present invention provides a switch means having two systems: a switch section that is turned on in response to the open state of the back cover, and a switch section that is turned on in response to the closed state. It is equipped with a power supply control means that detects the switch part on the side that is turned on in response to each action of opening and opening the back cover, and starts the power supply, so it can be easily configured and consumes no power. Since we have adopted a switch means that can detect the state and control the start of the power supply, the necessary state detection and power supply control can be configured with a simple circuit without wasting power consumption. It becomes possible.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
3 is a diagram showing the structure of the illustrated back cover switch, FIG. 3 is a diagram showing a switch structure having the same function as the switch illustrated in FIG. 2 in another embodiment of the present invention, and FIG. FIG. 5 is a diagram showing a switch structure having the same function as the switch shown in FIG. 2 in the embodiment, FIG. 5 is a diagram showing a DX electrode provided in the cartridge shown in FIG. 4, and FIGS. 6 to 11 are conventional configurations. FIG. l...Power supply, 3...Control unit, 1
2...Transistor, 31...Flip-prop, 32, 33...Resistor, 34...
...Back cover switch, 37.41...Inverter, 38.41...And gate, 39...
...Noah Gate, 44.46...Touch piece, 52
...Patrone, 55...Switch.

Claims (4)

[Claims] (1) Switch means having two systems: a first switch section that is turned on in response to the open state of the back cover, and a second switch section that is turned on in response to the closed state; A power supply control device for a camera, which includes a power supply control means that detects a switch section that is turned on in response to an action, and starts the power supply. (2) The switch means selects the first contact selected by opening the back cover, the second contact selected by closing the back cover, and the first and second contacts depending on whether the back cover is opened or closed. The first switch part is made up of the first contact and the contact piece, and the second switch part is made up of the second contact and the contact piece. Claim 1
Power control device for the camera described. (3) The first switch means is changed by opening and closing the back cover.
2. The power supply control device for a camera according to claim 1, comprising: a switch; and a second switch that changes depending on the presence or absence of a cartridge. (4) The power supply control means for controlling the power supply of the camera according to claim 3, wherein the power supply control means detects the state of the second switch that changes depending on the presence or absence of the cartridge and starts the power supply only when the back cover is opened. Device.