JPS59189406A - Sequence control device of camera or the like - Google Patents

Abstract

PURPOSE:To simplify the constitution of a circuit, and also to manufacture a titled device at a low cost by constituting said device so that the reference frequency can be switched on the way of sequency, and a dynamic range by a time base in sequence control of a camera, etc. is not so necessary. CONSTITUTION:A sequence control device of a camera, etc. is constituted of a reference frequency oscillating circuit, a sequence controlling circuit which is controlled by this reference frequency and also outputs a frequency switching signal on the way of sequence, and a switching circuit for switching the reference frequency by this frequency switching signal. As for the reference frequency oscillating circuit 7 for controlling the sequence controlling circuit 6, the oscillation frequency is determined by an internal resistance or a constant current source, and a capacitor C31. For instance, when the sequence controlling circuit 6 turns on a transistor Q31, the oscillation period becomes k(C31+C32), but in case of C31>>C32, the oscillation period becomes kC32, and the reference period can be enlarged remarkably.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention has a reference pulse oscillation circuit for a camera or the like that has a reference pulse inside and controls a system using this reference pulse, and uses all of this reference pulse. When controlling a sequence of cameras, a counter is used as a means to obtain the required pulse width.

Most of them were due to the use of flip-frogs, soft registers, etc.

Since all of these utilize only a single frequency as a reference pulse, they have the following disadvantages. Firstly,
Since the frequency of the reference pulse is usually set higher than the audible frequency, the number of stages in the frequency dividing circuit becomes extremely high when controlling the self-timer. For example, if the frequency of the reference pulse is 20kHz (period 50μ), 1
It is necessary to expand the pulse width by 200,000 times to make one hour of the self-timer of 0 seconds, and for this purpose, the dedicated frequency divider circuit is
This means that six stages must be connected. Second, as a matter of course from what has been stated above, the circuit becomes complex and large-scale, and when it is converted into a semiconductor IC, it becomes a factor that deteriorates the yield and increases the cost.

FIG. 1 shows a typical time sequence for an autofocus camera, and FIG. 2 shows a block diagram of an autofocus camera operating at a single reference frequency, as described below.

In FIGS. 1 and 2, when the shutter button of the camera is pressed, the switch S1 is turned on and the power is turned on. At this moment, each circuit block starts operating, but the sequence control circuit 1 is temporarily reset.

Next, the reference frequency oscillation circuit 20 reference frequency (period to
A battery check is performed with a pulse width determined by (this time is tl).

At this time, if the battery voltage is low, the sequence will not proceed. On the other hand, when the battery voltage is sufficiently high, the infrared light emitting diode L1 is then operated by the fingertip of the sequence control circuit 1 via the light emitting circuit 3, and emits light for a pulse width t2 time to the subject. The reflected light of this light is the optical sensor spc.

Returning to 5PC2, the arithmetic circuit 4 obtains an output corresponding to the distance. The time required for this calculation is assumed to be t3. Next, depending on whether there is a signal based on automatic exposure ('AE) information, the output of the arithmetic circuit 4 is prioritized, or the AE
Decide whether to prioritize information. This judgment time is defined as It4. The AE information here means that when the subject is very bright, the lens is narrowed down and the depth of field becomes deep, so even if the lens is fixed at a certain distance, it will be pan-focused. Subsequently, the display light emitting diode L2 lights up to indicate that distance measurement has been completed.

In the sequence up to this point, press the shutter button lightly <i[
This corresponds to the case of ii and can be repeated as many times as desired. Also, the total time is t1+t2+13+t (
=nto) or more is required.

Next, when the button is pressed further, the switch S2 is turned on. When using the self-timer, the self-timer's frequency dividing circuit works at the same time as this switch S2 is turned on, and the magnet Mqt○N starts moving the lens about 10 seconds after counting the reference frequency clock.
let While this frequency dividing circuit is working, the self-timer display light emitting diode L3id blinks at a cycle of about 1 second. On the other hand, when the self-timer is not used, the magnet Mq is turned on at the same time as switch S2 is turned on.
do. After the magnet Mq is turned on, the lens is returned to the front by the spring, and the output LP from the variable resistor V'R corresponding to the movement of the lens is compared with the calculation output, and the comparator circuit 5 is inverted at a certain voltage. (Magnet) Turn Mgi OFF and stop the lens. After the lens stops and focuses, the shutter opens for the shutter seconds to expose the film. The sequence thus ends.

Now, in the case of a lens shutter camera, the lowest value of the shutter speed is around Z3a seconds. Oh, switch S2
The maximum time from turning on until the end of exposure is about 100 m5ec when not using the self-timer, and about 10 seconds when using the self-timer. By the way, the above switch S1
The time from turning on to turning on switch S2 is n t o
It is better to make this time as short as possible, but in reality, it is necessary to take into account the circuit response9, the light emitting energy of the display light emitting diode, etc., and to make it inaudible to the human ear.
The reference frequency is determined between 20 kl (z and 100 klk). By determining the reference frequency as described above, a circuit that has only a single reference frequency as described above requires a very large dynamic range on the time axis. However, the circuit inevitably became complicated and the cost increased.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the conventional technology, and it is an object of the present invention to simplify the circuit configuration without requiring a large dynamic range on the time axis, and to manufacture it at low cost. The present invention aims to provide a 7-can control device for cameras, etc., which is capable of controlling the camera and the like.

Structure of the Invention In order to achieve this object, the 7-can control device for cameras, etc. of the present invention includes a reference frequency oscillation circuit, and is controlled by the reference frequency of the reference frequency oscillation circuit, and transmits a frequency switching signal in the middle of the sequence. The present invention is characterized by comprising a sequence control circuit for outputting the output, and a switching circuit for switching the reference frequency of the reference frequency oscillation circuit based on the frequency switching signal. According to this configuration, the reference frequency can be switched in the middle of the sequence, so a dynamic range on the time axis is not necessary in sequence control of cameras, etc., and the circuit configuration can be simplified accordingly. In addition, when it is made into a semiconductor IC, it can be manufactured with a high yield.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below, including the time sequence of FIG. 1 as well as FIG. 3. In Figure 3,
C31 and C32 are capacitors, and are referred to as C31) and C32. C31 is a transistor that functions as a switch that is turned on and off by a signal from the sequence control circuit 6. The reference frequency oscillation circuit 7 that controls the sequence control circuit 6 has an oscillation frequency determined by an internal resistor or constant current source (not shown) and the capacitor C31, and its oscillation period is t3°. Then, t3
It is expressed as 3C31 (k3 is a constant of proportionality) in °-. Here, at the moment when the switch S2 is turned ON in the sequence shown in FIG.
2 should be connected in parallel with the capacitor c31, and the oscillation period (t30
') is null as t30' ``k3 (C31 + C32).
Figure 4 shows another embodiment of the present invention, in which capacitors C31 and C32 and transistor Q31 in Figure 3 are used.
The equivalents are capacitors C41 and C42 and transistor Q41. In FIG. 4, capacitor c41. c.
42 are connected in series, and in the sequence shown in FIG. 1, it is assumed that the transistor Q41 is OFF from the time when the switch S1 is turned on until just before the switch s2 is turned on. )
becomes. Next, at the moment when the switch s2 is turned on, the transistor Q41 is turned on by the action of the sequence control circuit 6. Then, the oscillation period t40' becomes 4C42 at t4ol=, and the period can be greatly increased as in Fig. 3. becomes possible.

While the embodiments shown in Figures 3 and 4 above change the oscillation period by changing the capacitance of the capacitor, other embodiments change the period by changing the resistance value. is shown in Figure 5. In Figure 5) C51
9R51, R52, and Q61 represent a capacitor and a resistor (Rsl<<R52) transistor, respectively. In the sequence shown in FIG. 1, turning on switch S1
Assuming that the sequence control circuit 6 controls the transistor Q61i0H from 1 to 1 until just before the switch S2 is turned on, and then turns it off immediately after the switch S2 is turned on, the oscillation period is initially 5C51R61 at t5o=
1 followed by 5C61 (R51+R52)- at t50'-
becomes 6C51R52 (however, k5 is a proportionality constant).

Here, since R52)R51, it becomes t5o/)t6o, and the period can be changed significantly as in FIGS. 3 and 4. , and the resistors R51tR52'' can be configured in parallel connection instead of series connection in the same way as in the case of a capacitor.

FIG. 6 shows still another embodiment of the present invention, showing two examples in which the oscillation period is changed by a constant current source.

In FIG. 6, "61t" 62 is a constant current source; 2
〉〉■. 1. In the sequence shown in Figure 1, the oscillation period It6° is just before the switch S1 is turned on and the switch S2 is turned on, during which the switch S is turned on and the switch S is turned on.
Assume that the oscillation 1 period after 2 is turned on is t6゜', and the switch S61 is OFF.
t60 = 6C61/work 61+work 62- 61C61/
C62t60'- becomes 6C61/work61 (k6 is a proportionality constant). Here, since I > I, t6゜(t6
o'62 61 , and the oscillation period after the switch S2 can be greatly increased.

In the above embodiment, the sequence of the autofocus system of the camera shown in FIG. 1 is taken as an example, and the switching timing of the reference frequency is set by the switch S2 in FIG.
It is desirable to change it at the most effective timing for each system, without being particular about this. Although a transistor is used as a switch in each of the embodiments shown in FIGS. 3, 4, and 5, any transistor having a switch function may be used instead.

Effects of the Invention As described above, the sequence control device for cameras, etc. according to the present invention is configured so that the reference frequency can be switched in the middle of the 7th cycle. Dynamic range is no longer necessary, and as a result, the circuit configuration can be simplified, and when semiconductor ICs are used, they can be manufactured with high yield, contributing to cost reduction, etc. It's a dog.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining a general time sequence of an autofocus camera, Fig. 2 is a block diagram of an autofocus camera operating at a single reference frequency, and Figs. 3 to 6 are sequence control in the present invention. FIG. 2 is a block diagram showing an embodiment of the device. 6... Sequence control circuit, Y... Reference frequency oscillation circuit, C31... First capacitor,
C32...Second capacitor, Q31...
・Name of Transistou agent Patent attorney Satoshi Nakao
Male and 1 other personFigure 1Figure 2CE informationFigure 3Figure 4

Claims (2)

[Claims] (1) a reference frequency oscillation circuit, a sequence control circuit that is controlled by the reference frequency of this reference frequency oscillation circuit and outputs a frequency switching signal in the middle of the sequence, and a sequence control circuit that outputs a frequency switching signal in the middle of the sequence; 1. A 7-can control device for a camera, etc., comprising a switching circuit for switching a reference frequency. (2) The reference frequency oscillation circuit includes a first capacitor and a first
The switching circuit comprises a transistor and a second capacitor, and the switching circuit comprises a transistor and a second capacitor.
A sequence control device such as a camera described in Section 1.