JPS5852278B2 - Syashinyoukeisuouchouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital information counting device, and more particularly to a counting device for an exposure control device used in a digitally controlled camera or the like.

One of the digital shots is directly converted into an electrical signal by mechanical means, this pulse signal is counted, and the output is compared with the digital value of other preset shooting information to obtain a matching output. This is a counting device for use in a digitally controlled camera in which a preset mechanical displacement is obtained by controlling said mechanical means.

Conventionally, various photographic information is digitized and calculated, and the output pulse of an exposure calculation circuit that is set according to the shutter speed, film sensitivity, and subject brightness is used to control the aperture mechanism of the lens actually used for photographing. The aperture information of this lens is replaced with a resistance value, and by passing a constant current through this resistor, the aperture information is converted into an electrical quantity.The analog information obtained thereby is converted into digital information, and this is used for various types of photography. A method is known in which the aperture information is obtained by comparing the calculated output from the information.

The conventional device as described above requires an A-D converter and therefore has a complicated circuit configuration, which has many disadvantages when incorporated into a small camera or the like.

The present invention relates to an improvement in a counting device for an exposure control method in which the aperture information used in actual photography is directly generated as a digital signal without obtaining it as analog information, and digitally controls the shutter speed or aperture mechanism using this digital signal. The purpose of this method is to prevent erroneous counting due to the chuckling phenomenon that occurs when the two contact each other when counting the number of contacts between the comb-like conductor pattern and the brush sliding on it. It is something to do.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a circuit diagram of a digitally controlled camera to which a counting device according to the present invention is applied.

In the figure, 1 is a photoelectric conversion element 34b with a fast optical response speed, such as a silicon photocell, an operational amplifier 2',
This is a photometry section consisting of a logarithmic compression diode 3' inserted in the return path.

4' is an AD converter which converts the analog output of the photometer 1 into a digital value.

5' is a memory section consisting of a register, and a memory switch SM
The digital output of 1 is stored when the switch is on.

An adder 6' adds the subject brightness information BV in the register 5' and the logarithmically compressed and digitized film sensitivity information Sv.

7' is a subtracter which uses the output of adder 6' as one input, and the other input is connected to a switch sP in the case of shutter priority.
Logarithmically compressed and digitized shutter speed information Tv is inputted via a shutter control switch ST, and in the case of aperture priority, logarithmically compressed and digitized aperture information AV is inputted via a shutter control switch ST.

12' is a register in which AV is stored when shutter priority is given, and Tv is stored when aperture priority is given.

Reference numeral 10' denotes an aperture step number pulse generation circuit which generates a step number pulse in conjunction with the aperture mechanism of the lens.

SP is a manual switch and is turned on when shutter priority is selected.

A register 11' stores the output pulse from the pulse generating circuit 10 via a switch SP.

Reference numeral 9' denotes a comparison circuit which generates an output pulse when the aperture value stored in the register 12' matches the pulse signal of the register 11', and activates the aperture control magnet Mg2 via the switch SD.

8' is a delay circuit that drives the front curtain magnet Mg3 when the mirror finishes rising after the shutter release.

Reference numeral 14' denotes a time setting circuit, which drives the trailing curtain magnet Mg4 after the shutter time set in this circuit and after the calculated shutter time.

13' is a register, A is a shutter dial, L is a lamp, SD is a magnet switch that works with the manual switch sP, and ST is a pulse signal that is connected to the register 13.
' is the shutter control switch that is transmitted to 'S'.
This is a switch that works with T.

SPl is the display switch, and the lamp switch SL
SL' is linked, Sw is a manual control switch,
During manual mode, shutter speed information is transmitted to the timer circuit.

FIG. 2 is a circuit diagram showing one embodiment of the counting device according to the present invention, shown as the aperture stage number pulse generating circuit 10' in FIG.

In the figure, reference numeral 101 denotes a comb-like conductor pattern, in which a conductor as shown made of a metal film or the like is disposed on an insulating substrate (not shown), and a sliding brush 102 slides on this pattern in the direction of the arrow. The contact between the conductor and the brush generates a pulse signal.

103 is a conductor pattern for generating a start signal placed at one end of the pattern 101 ov, and the sliding brush 102 starts from this position and slides on the comb-like pattern.

104 is a first binary counter, and the signal from the brush 102 is applied to a clear terminal of 104 to control the counting of clock pulses input from the CP terminal.

A clock pulse generator 105 is composed of, for example, an astable multivibrator, and generates pulses of a constant period.

106 is an AND gate whose output is input to the CP terminal of 104 above.

A first counter 104 is controlled by a signal from brush 102 to count clock pulses from CP and produces binary-coded pulse outputs at its output terminals 1, 2, 4.8.

Output pulses from "4" of the 104 output terminals are input to the CP terminal of the second counter 108, where they are again counted in binary.

Further, the pulse from output terminal "8" of 104 is input to the AND gate via inverter 107, forming a closed loop.

The output of the second counter 108 is input to a comparator 109, and to the other input of this 109, a digital preset signal is input from a preset signal source 110 for photographing information, and when they are compared at 109 and match, 109 The output from 0109, which produces an output, is converted into a mechanical displacement amount by the electro-mechanical conversion means 111, and the sliding of the sliding brush is controlled and stopped.

As described above, digital information corresponding to the sliding distance of the brush 102 from the starting position is obtained, and with this, for example, the aperture mechanism is controlled and the aperture value is determined.

FIG. 3 is a curve diagram showing a timing chart for explaining the operation of the circuit of FIG. 2.

In FIG. 2, when the power switch (not shown) is closed, the pulse generator 105 generates a clock pulse with a constant period as shown in FIG.
is input to the CP terminal of the counter 104, and 2 is input at 104.
It is counted in decimal.

When the brush 102 slides on the pattern 101, a start signal is first input to the clear terminal of the pattern 104, and counting is started from this time.

Output terminals rlJ, r2j of 4-bit counter 104
, r4JJ8J sequentially output binary codes, of which terminals ``1'' and ``2'' are unused, and terminal ``4'' is connected to the second counter.

Further, the terminal "8" is inputted to the AND gate 106 via the inverter 107 and connected to the input terminal CP of 104 in a closed loop.

Therefore, the counter 104 does not count after the count value 8.

FIG. 3 shows a signal from the brush that causes chattering as shown when it comes into contact with the pattern.

In order to avoid this, the output of 104 only outputs the signal that occurs at terminal "4" during the period from count 4 to count 7, as shown in FIG. 3C.

Also, in order to eliminate malfunctions caused by the counter counting twice or more because the sliding speed of the brush is slow compared to the period of the clock pulse, in this embodiment, after count 8, the clock pulse is blocked by the AND game H1)6. This is to prevent the data from being input to the counter 104.

Therefore, a signal corresponding to the number of contacts between the brush and the pattern is reliably input to the CP terminal of the second counter 108.

If the period of the clock pulse is selected to be sufficiently high relative to the sliding speed, an accurate output signal can be obtained as described above.

The output pulses shown in FIG. Controlled and stopped.

Next, FIG. 4 is a circuit diagram showing another embodiment of the counting device according to the present invention.

In the figure, the same parts as in FIG. 2 are designated by the same reference numerals.

In the embodiment of FIG. 4, the first counter 104' has, for example, 7
Using a bit binary counter, ``4'' of its output terminals
The above information is input to the second counter 108 via the OR gate.

In this circuit, similar to the one in Fig. 2, in order to eliminate the influence of brush chatter, the counters rlJ and r2J are
The output terminal ``4'' is not used, and the input signal to the second counter 108 is generated from all outputs after output terminal ``4''.

Counter 10 even if the brush sliding speed is quite slow
By using 7 bits for 4', the counter 104 is cleared by the signal from the next brush while the counter counts one clock pulse.
The output signal of ' is a number corresponding to the number of contacts between the brush and the pattern.

In addition, if the sliding speed of the brush is extremely slow and the clock pulse period is extremely fast, the counter output will be 2 or more relative to the number of brush contacts, resulting in malfunction.
The period of the clock pulse must be chosen appropriately for the slowest brush speed.

The other circuit configurations and operations are similar to those of the embodiment shown in FIG. 2, and their explanations will be omitted here.

FIG. 5 is a circuit system diagram showing a third embodiment of the present invention, and FIG. 6 is a curve diagram showing an example of a timing chart of the circuit shown in FIG.

In the figure, the same parts as in FIG. 2 are designated by the same reference numerals.

In this embodiment, the clock pulse generator 105' uses a variable frequency type, and the first counter 104 uses a 4-bit type, and the signal from its output terminal "8" is transmitted to the second counter 108. is input to the CP terminal of.

The operation of this circuit is achieved by varying the frequency of the clock pulse shown in Figure 6a in accordance with the sliding speed of the brush.
Counts after 8 on the 4-bit counter, i.e. 8 to 1
The output of 5 forms the input signal to the second counter 108.

In this way, if the frequency of the clock pulse is changed according to the brush speed, even if the brush speed is fast or slow,
Since only one output signal of 104 can be generated for one contact, malfunctions will not occur.

Figure 6 shows the case where the brush speed is the fastest, and in this case it is 10
Signal C is formed by only 8 outputs out of 4 outputs, and is cleared after 9 outputs.

Also, FIG. d shows a case where the brush speed is the slowest, and in this case, the frequency of the clock pulse becomes slow and the signals 8 to 15 of the outputs 104 form a signal as shown in FIG. e.

FIG. 7 is a plan view a showing an embodiment of the comb-like conductor pattern used in the counting device of the present invention, and a curve diagram showing brush sliding characteristics.

In the figure, 101 is a comb-shaped conductor pattern, 102 is a sliding brush, 103 is a start position signal pattern, 12
0 is a common return pattern, 113 is an insulating substrate, 114°1
15 is a connecting conductor from the pattern.

These patterns 101, 103, and 120 are fixedly disposed on an insulating substrate 114 using a conductor piece or a method such as vapor deposition, and the sliding brush 102 moves on the insulating substrate 114 with uniform acceleration as shown in the right direction from the starting position S. slide.

Reference numeral 103 is a start pattern arranged independently at the sliding start position of the brush, and by sliding this, a start position signal is obtained. In addition to clearing the second counter as shown in FIGS. 4 and 5,
It has the role of reducing wear in the initial pattern.

120 is a common return pattern provided in parallel to the comb-like pattern 101;
115 are drawn out from opposite ends as shown.

This prevents the resistance value within the pattern from changing depending on the sliding position.

In the figure, P and Q are the conductor widths in the sliding direction of the comb-like pattern, and the widths are changed in accordance with the brush speed shown in the figure.

In addition, e''-n in Figure a is the stopping position without taking into account the sliding speed of the sliding brush. It is arranged to be corrected in the front.

This is to compensate for time delays caused by the electromagnetic magnet that causes the brush to stop, mechanical delays in other partial movement mechanisms, and the like.

In Fig. 7, α is the acceleration when the brush is moving at a constant acceleration, S′ is the distance from the start position of the position where the brush actually slides and stops from the generation of the pulse, and is the above-mentioned time at this time. If the delay is T, the distance from the start position of the pulse generation position is 81, the time from the start to the pulse generation is t, the interval between each stop position is l, and the number is n, then the pulse generation position S is as follows.

In equation (4), l is constant, so n. The shape of the comb-like pattern can be determined by calculating R, [J, V, .

Since the movement after m' in the figure is constant velocity, the pattern for this will be an equally spaced pattern.

FIG. 8 is a perspective view showing the sliding state of the comb-like conductor pattern 101, the common return path pattern 120, and the sliding brush 102. By arranging both patterns as shown in FIGS. 7 and 8 a, This shows that a sliding brush with a simple structure as shown in FIG. 8a can be used.

In the case of a pattern arrangement as shown in FIG. 8, it is necessary to use a brush having a structure as shown in the figure, and the cost will be higher than that shown in FIG. 8a in terms of the structure and other aspects of the brush.

As described above, in counting the digital signals obtained by the mechanical displacement means, the counting device according to the present invention forms a closed loop by outputting a coincident value with a calculated value or a precent value of digital information other than the above, and counts the digital signal obtained by the mechanical displacement means. The digital information obtained from this can be highly accurate and stable, and its effects are particularly great when applied to digital control devices such as cameras. It is what it is.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of a digital control camera to which a counting device according to the present invention is applied, FIG. 2 is a circuit diagram showing an example of a counting device according to the present invention, and FIG. A curve diagram showing an example of a timing chart for explaining the operation, FIG. 4 is a circuit diagram showing another embodiment of the present invention, and FIG. 5 is a circuit diagram showing a third embodiment of the present invention. FIG. 6 is a curve diagram showing an example of the timing chart of the circuit shown in FIG. Fig. 8 is a curve diagram showing the brush sliding characteristics, and Fig. 8 is a perspective view showing the arrangement of the comb-shaped conductor pattern, the common return path pattern, and the sliding brush. 1...Photometering section, 2'... ...operational amplifier,
3'... Logarithmic compression diode, 34b...
...Photoelectric conversion element, 4'...A/D converter,
5'...Storage unit, 6'...Adder, 7
'...Subtractor, 8'...Delay circuit, 9
'...Comparison circuit, 10'...Aperture stage number pulse generation circuit, 11'12', 13'...Register 14'...Time constant circuit, Mg2...
...Magnet for aperture control, Mga...Magnet for front curtain, Mg+...Magnet for rear curtain,
A...Shutter dial, ST...
Shutter control switch, STl...Switch, SP...Manual switch, SP
l...Display switch, SP〃...Switch, SL? SL'・・・-・Lamp switch,
L...Lamp, Sw...manual control switch, SL)...switch, SM...
... Memory switch, 101 ... Comb tooth groove body, 102 ... Sliding brush, 103 ...
Start position conductor, 104, 104'...1st
counter, 105... clock pulse generator,
106...AND gate, 107...
Inverter, 108...Second counter, 10
9...Comparator, 110...Preset signal source, 111...Electro-mechanical converter, 112
...OR circuit, 105'...Variable frequency pulse generator, 113...Insulating substrate, 114,
115... Connection conductor.

Claims (1)

[Claims] 1. A start position conductor, a conductor pattern consisting of a number of contacts located in a predetermined direction at a predetermined interval in contact with the start position conductor, a brush that slides on the conductor pattern, and a brush that slides on the conductor pattern at a predetermined speed. and a clear terminal electrically connected to the brush, which is brought into a clear state by falling and trailing edges of a signal generated as the brush slides, and which outputs a clock pulse from a clock pulse generator. a first counter for counting, and a second counter having a clock pulse input terminal connected to a predetermined digit output terminal of a binary output terminal of the first counter, and a clear terminal connected to the start position conductor. a counter, a comparator that compares the count output value of the second counter with a digitally calculated value or a set value of various photographic information obtained in advance, and outputs a coincidence signal when there is a match; A counting device that converts digital information obtained in advance into a mechanical displacement defined by a start position and a stop position of the brush, the counting device comprising means for stopping the sliding of the brush in response to a coincidence signal from the brush.
An output terminal of the clock pulse generator is connected to one input terminal between the clock pulse generator and the first counter, and a digit output is larger than the predetermined digit output terminal of the first counter. An AND gate circuit whose terminal is connected to the other input terminal via an inverting circuit and whose output terminal is connected to the clock pulse input terminal of the first counter is provided to prevent counting of clock pulses more than necessary. A photographic counting device featuring: