DE2462587A1 - ELECTRONIC LOCK - Google Patents

Description

PATENTANWÄLTE 8 MÜNCHEN 86, POSTFACH 86 02 45

Attorney's file 28 159

16th time 1977

RICOH COMPANY LTD. Tokyo / Japan

Electronic lock

The invention relates to an electronic lock egelreflexkaniera for a one-eyed mirror of the type specified in the preamble of claim 1.

In an electronic shutter for a single-lens reflex camera the amount of light incident through a photographic lens must be temporarily or momentarily stored will. The amount of light extends over six

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_ ₂ _

t (I) SiI IRK2 12 8 Munich 80, MaucrkirthcrstraUe 45 Banks: Bayerische Vereinsbank Munich 453100

• »» ■■ 043 telegrams BPRGSTAPITATENT Munich Hypo-Bank Munich 3890002624

W.1310 TtIXX 05 24 560 BÜRG d Postscheck Munich 65343-808

Decades (10 to 10), which complex elements and required complicated wiring when attempting digital photoelectric conversion, but which can be processed in a compact arrangement with only a single line, if a analog processing is applied. On the other hand, when an analog voltage is stored, which is used for formation shutter speed is used, then digital storage is in view for a flawless maintenance (of the stored value) even after a longer storage period in comparison to an analog storage in a capacitor or something similar advantageous or preferable. Since a digital display is also preferable as a display on a viewfinder, it can be seen from this that digital storage brings greater benefits. If the stored value is used to determine a Shutter speed or exposure time is taken, the time segment or period can be in the form measured by reference clock pulses, which in turn has the advantage that any resulting error is only one Is a fraction of a clock pulse, so that in this way in comparison to a method that works in analogue which an integration takes place on a capacitor or something similar, even with an exposure via one A high level of accuracy is achieved over a longer period of time. The use of logic circuits enables it

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in addition, a logarithmic expansion of a logarithmically compressed, analog signal, without that the conversion or conversion accuracy as a result of changes or deviations from product to product, as a result of temperature changes, among other things, adversely affected becomes, which can certainly be the case with an analog stretching or expansion.

With the present invention, therefore, an electronic lock should be created in which the effort for the circuitry of the camera can be reduced.

This is according to the invention by the in the characterizing part of claim 1 specified features solved.

The advantages achieved with the invention are based in particular that an integrated circuit with a high degree of integration, a so-called LSI circuit, is used can be. This extensive integration results in a very compact structure, so that the electrical Circuit can be greatly miniaturized »as is particularly the case with today's trend towards small, compact cameras is essential.

The invention is illustrated below with the aid of exemplary embodiments explained in more detail with reference to the accompanying schematic drawings.

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"* ■ 2A62587

Show it:

Fig. 1 is a block diagram of the circuit structure of an electronic shutter for a one-eyed Reflex camera; and

Fig. 2 shows a circuit structure in which an integrated A circuit with a high degree of integration, a so-called LSI circuit, is used.

1, a light receiving element 1 for photoelectric Uses conversion of light transmitted through a photographic lens, and is connected to a sensor amplifier 2, which in turn is connected to a logarithmic compressor circuit is to convert a geometric series, which represents the amount of incident light, into an arithmetic series

2 he implement, where 1 in 0, 10 in 1, 10 in. 2,

10 is converted into 3 etc. The output of the logarithmic Compressor circuit 3 is connected to a temperature compensation or compensation circuit 4, whose Output of an analog arithmetic unit 5 is fed to the is in turn connected to a peak detector 6.

The logarithmic compressor circuit 3 is used to compress or compress six decades to one low voltage on the order of one or two

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Volts used. The information concerning the amount of light i ⁿ in the analog processing unit 5 has been implemented a voltage (may be that, for example, 100 mV / 1 EV) is in accordance with the film sensitivity swert (ASA) and the aperture value (both of which, for example, 100 mV per Step or step), whereby an analog voltage for the formation of a shutter speed or an exposure time (in the following only exposure time is spoken of) is obtained, and which amounts to 100 mV per exposure time step. With the help of the peak detector 6 it is ensured that a stabilized output is obtained for a light source, for example a fluorescent tube or lamp, which flashes or lights up at a low frequency; furthermore, the light from the digital display device or the fluorescent tube or lamp, which is arranged in the viewfinder, can be canceled or eliminated with the tip detector, as will be described later.

An analog switch 7 can be an automatically created one Output from the analog computing unit 5, a manually set output from an output that creates the exposure time Resistor 8 and received an output from a battery. A 6-bit analog-to-digital converter 10 is designed so that it creates a number of digital outputs, for example a total of 4t2 digitized outputs, if the preset values of the film speed incre-

7098A1 / 0016

ments or steps of a one-Brittel stage, with an aperture value stage being divided into a one-third increment or step and a one-third step each for an exposure time of 1/1000 to 8 sec. as well as two exposure periods under 1/1000 sec. and over 8 sec. which are each outside the chained work area, ie (13x3 + 1) + 2 = k2.

The analog-to-digital converter 10 is supplied with a pair of storage-defining signals from terminals 18 and 19. Here, terminal 18 provides a signal to determine storage immediately before the light is picked up by the mirror, while terminal 19 is provided to supply a signal to determine storage by means of an externally performed manual operation. Furthermore, a connection 20 is provided for switching from automatic to manual operation. A logic circuit 11 receives the output of the converter 10 and forwards it to a counter 12, which counts the reference pulses from an oscillator 13 at the same time as the start or start of the first curtain, when the stored digital information is introduced into the logic circuit 11. In this case, the arrangement is designed so that when the number or the counter reading in the counter 12 corresponds to the value entered into the logic circuit 11, an electromagnet Ik is actuated to actuate the lock.

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The Riock 15 is part of the arrangement, by means of which a correct exposure is determined digitally by using the so-called zero method in manual operation is used. By means of a display decoder 16, a stored exposure time representing, digital value converted into a voltage for switching on a light-emitting diode arranged in the viewfinder, in order to thereby to enable a digital display.

As stated in the understanding, with the electronic shutter according to the invention, in which, as described in connection with Fig. 1, means for fixing or determining a storage is used, a storage determining or determining signal, a Solenoid triggering signal and a control signal are applied, with all signals applied via plug pins which must be connected to a so-called LSI unit, i.e. a unit with a high degree of integration are appropriate. When the prescribed electrical circuit as an integrated unit with a high degree of integration is executed, the pins result in higher costs and a less compact structure. An enlargement or extension of a single pin can prevent the integrated unit from being required in a Size is carried out by preventing the integrated unit from loading because of the requirements

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plus the packing density, ie accommodating as many elements as possible in a small space at a given location in a camera. As a result, if the electrical circuit is to be designed as a so-called LSI unit, ie an integrated unit with a high degree of integration or group integration, the number of pins should be reduced to a minimum. In Fig. 2 it is therefore shown that _; If the electrical circuit of the figure is in the form of an LSI unit, ie, as an integrated circuit, the control pin to which the signal defining or determining the storage is applied, as well as the control pin to which the electromagnet triggering signal is applied are used in common.

According to the invention, the LSI or integrated circuit has a storage determining or determining unit kk and a period converter Λ6 in addition to the logic circuit shown in FIG. The output of the period converter kd is connected to the base of a transistor Tr2 via a resistor R1, the KolMor of which is connected to a control pin A. The pin A is also connected to a voltage supply line Vcc, so that in this way a voltage is supplied via the pin A to the storage specifying device kk. The pin A is also connected through a resistor R2 to the base of a transistor TrI, the collector of which is connected to an electromagnet Mg,

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which is provided for moving and shifting the second curtain of the shutter. A resistor R3 is connected between pin A and the + E power line while a normally closed Switch SW 1 is connected between the power supply line -E and pin A. over its emitter is that Transistor TrI also connected to the line -E.

In addition to the pin .bzw. Pin A is provided with another pin or pin B in the integrated unit, the so-called LSI unit. Pin B is connected to a normally closed switch SW2 and a resistor Rk ; In this case, the arrangement is designed so that a control signal is applied to the period converter 46 when the switch SW 2 is opened. The switch SW2 is opened when the first curtain of the shutter runs or is moved. It should also be mentioned that the switches SW1 and SW2, the electromagnet Mg and the resistors R2 to R ^ are arranged outside of the integrated unit, the so-called LSI unit. The switch SW1 can be opened by means of a lock during an upward movement or when a sliding or pivoting mirror in the camera is folded up, in order to release the paeotographic path. When it, ie the switch SWi, is open, the signal defining the storage and the trigger signal for the electromagnet Mg are applied to the pin A '.

If a shutter release is pressed during operation

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is to take a picture, then the movable or flip-up mirror folds up to open the photographic path and free. As a result of such a pivoting movement, the switch SV / 1 is then opened, as a result of which the potential "at pin A assumes a high level, which creates a signal defining the storage and a signal that triggers the electromagnet. The signal defining the storage is then sent to the appropriate device 44- is applied to actuate it, while the solenoid triggering signal is applied through resistor E2 to the base dps transistor Tr1 so that it becomes conductive and thereby actuates the electromagnet Mg. When the electromagnet Mg is energized, the second becomes "The shutter curtain is forced to run or move while the first curtain runs over the image format and initiates an" exposure.

When the first curtain moves, the switch SV / 2 is opened, giving a control signal to the period counter 46, which then starts counting an exposure period; if then the counter reading in the converter 46 corresponds to a stored value * then the output of the period converter 46 inverts to a high level, causing the potential at pin A to be raised switches to a low level, whereby the passage through the transistor Tr1 is interrupted and this is not

is more conductive. When the transistor Tr1 is no longer conductive is, the electromagnet Mg is de-energized, which then no more force or pressure is exerted on the second curtain of the closure, so that this is then immediately 25U starts running and a corresponding shutter speed the recording process ends. In the circuit of the Pig. 9 the resistor R3 can also be integrated in the Unit, the so-called LSI unit.

- patent claims -

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Claims (2)

Claims 1. Electronic shutter for a single lens reflex camera with a photoelectric building Lenient, whose Output signal in a bvw to be set. to be displayed exposure value is converted, characterized by the analog voltage into a converting the digital value and temporarily changing the digital value storing analog / digital converter (10) a logic circuit (ll) and by a Periodenzdh-. ler (12), the exposure time from your stored value form, the analog / digital converter (10) and the logic circuit (11) for the exposure time are integrated into an LS'I circuit. 2. Electronic lock according to claim 1, characterized in that that the period converter (46) in (Jie LSI circuit "is integrated. 3 · Electronic lock according to one of Claims 1 or 2, characterized by an electrical switch (SW1), which is opened to generate a signal corresponding to the pivoting movement of a mirror in the camera or is closed, and by a facility (TrI)., the the signal from the switch (SWl) at the end of the period conversion interrupts, the signal from the electrical switch (SWl) both as a storage 709841/0016 - 13 - λ ' defining signal as well as a shutter triggering signal is used. 709841/0016