JPS603168B2 - Camera proper exposure confirmation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera, and more particularly to a proper exposure confirmation device for a camera using a film holder loaded with raw film.

In general, in cameras, the amount of exposure to film is
It is determined by the aperture degree of the aperture mechanism incorporated in the optical system and the shutter speed of the shutter mechanism, and it is assumed that both mechanisms operate normally, and the correlation between the aperture degree and shutter speed is determined. The person in charge takes photos based on their experience and by setting the settings with the help of a light meter.

However, if this assumption breaks down, for example,
If the aperture mechanism or shutter mechanism breaks down or malfunctions, or if the flash does not synchronize, this will naturally lead to a failure in shooting, and the same can happen if the aperture or shutter speed is set incorrectly. It's fine when you can check these things from the operation surface, but when you can't check them, there's nothing you can do about it, and not only do you lose valuable photo opportunities, but when you can't take the picture again, this becomes a fatal flaw in the camera. Currently, the same scene is usually photographed at several schools under different conditions.

That is, in conventional photography, it was only possible to determine whether the film was a success or a failure, in other words whether or not it had been properly exposed, until it was developed. In view of the actual situation of photography using this type of camera, the inventors of the present invention have effectively determined the above-mentioned circumstances and have accomplished the present invention.

The purpose of the present invention is to measure the amount of light transmitted through the film in this type of camera, so that it can be confirmed whether the exposure was appropriate at the time of shooting, and at the same time, the amount of light transmitted through the film is measured. To provide a proper exposure confirmation device for a camera, which makes it possible to confirm whether the set aperture degree and shutter speed are appropriate even before loading, and perfects photographing by this type of camera.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is an explanatory diagram of a flock of the appropriate exposure confirmation device according to this embodiment, and Fig. 2 is an external view of the overall configuration. It is applied to a camera that has an optical system 1 consisting of an aperture mechanism 3 and a shutter mechanism 4, and uses a film holder 5 that shields raw film 7 loaded on a partition plate 6 from the outside with a pullable lid 8 that can be freely inserted and removed. ,
The film 7 is exposed by the optical system 1 with the sliding lid 8 pulled out, and after exposure, the sliding lid 8 is inserted again and taken out.

The present invention is applied to a camera using such a film holder 5.

Its structure includes the partition plate 6 of the film holder 5.
It has an insertion section 9 that can be detachably inserted into the back surface of the device, and an operation section 10. The insertion section 9 receives light transmitted through the film 7 when loading a film, and outputs a current proportional to the amount of transmitted light, corresponding to the position of a transparent window 6a formed at the center of the plate surface of the partition plate 6. In addition, an optical flea conversion element 11 is provided which directly receives light when no film is loaded and outputs a current proportional to the amount of fog light. The operation unit 10' also includes a power supply circuit 12, an increase circuit 13 for increasing the detection power of the photoelectric conversion element 11,
A light transmittance setting circuit 14 that sets an appropriate amount of transmitted light to be obtained by passing through the film under conditions such as the density of the photosensitive emulsion and packing of the film 6, that is, the light transmittance of the film used. , the current limiting circuit 15 , and the exposure sensitivity (A
The exposure sensitivity setting circuit 16 provides a condition for SA). A change-over switch circuit 17 switches the increasing output of the increasing circuit 13 to the light transmittance setting circuit 14 when the film is loaded, and to the current limiting circuit 15 when the film is not loaded. and an A-D converter circuit 18 that converts the output that has passed through the current limiting circuit 15 into a digital value, and determines whether the digital value obtained from this A-D converter circuit 18 is too small, appropriate, or too large. and a determination circuit 19 for outputting the output from the determination circuit 19.Then, depending on whether the output of the determination circuit 19 is too low, appropriate, or excessive, for example, the appropriate output is determined by the blue light emitting diode 20a, the output is determined by the blue light emitting diode 20a, the output is determined by the blue light emitting diode 20a; The residual voltage discharge of the photoelectric conversion element 11 and the display circuit 20 in which the red light emitting diodes 20b to 20e display the 1,0G and the display is held by the holding circuit 21 and the start switch 22a are closed. An operation circuit 23 for holding and releasing the display circuit 21 and a start circuit 22 having an indicator light 23a for confirming the operation are provided.In addition, the light transmittance and exposure sensitivity setting circuit 14, 16, depending on the brand of film 7 used, the dial knob 24 can simultaneously give the light transmittance and exposure sensitivity. The output A is obtained by giving light transmittance and exposure sensitivity conditions to the amount of light.In addition, in the current limiting circuit 15, the amount of fog light that can be obtained directly without using the film 7 by turning off the so-called empty shutter is obtained. Since it is impossible to judge this equally with the output A,
The output value B is obtained by reducing the output value at a constant rate and then applying the exposure sensitivity conditions described above. Therefore, in this case, as will be clear from the explanation below, the output A
The amount of light given to film 7 is
The output B serves as a judgment value for determining whether the amount of exposure light to be given to the film 7 is appropriate for this film 7,
Regardless of whether the camera is normal or not, depending on the output A, the quality of the shooting result can be confirmed, and the output B
This means that it is possible to predict whether the photographing results will be good or bad depending on the situation. Furthermore, the change-over switch 17a of the change-over switch circuit 17 not only switches between loading and unloading the film, but also turns the power supply circuit 12 on and off.

Furthermore, the determination circuit 19 determines whether the output A or B
The digital value obtained by A-D conversion of It determines whether the following applies and outputs the result. Next, to explain the operation, when the film 7 is loaded, first switch the selector switch 17a to turn on the power supply circuit 12, and also switch the increaser circuit 13 to the light transmittance setting circuit 1.
4, and by operating the dial knob 24, depending on the brand of the film 7, the exposure sensitivity and light transmittance are set in the exposure sensitivity setting circuit 16 and the light transmittance setting circuit 14, respectively.

Furthermore, by operating the start switch 22a, the residual voltage of the photoelectric conversion element 11 is discharged and the holding circuit 21 is released.Then, the aperture mechanism 3 and shutter mechanism 4 of the optical system 1 are set, and the sliding lid 8 is pulled out. , the shutter 4 is released and the film 7 is exposed. With this operation,
The light transmitted through the film 7 is received by the photoelectric conversion element 11, producing an output proportional to the amount of transmitted light, and this output is intensified by the intensifying circuit 13, passes through the light transmittance setting circuit 14, and becomes the output A. Also, this output A is the A-D converter circuit 18
The obtained digital value is A-D converted by the judgment circuit 19 to determine which of the reference values it corresponds to, and if it is appropriate, the blue light emitting diode 20a of the display circuit 20 is Alternatively, if the amount of exposure is too much, the red light emitting diodes 20b and 20d will similarly emit light, and if the amount of exposure is completely too little or too much, the red light emitting diodes 20c and 20e will similarly emit light respectively, and the exposure amount will be displayed respectively. It can be confirmed that the display is correct, incorrect, or completely incorrect, and these indications are held by the holding circuit 21.

When the film 7 is not loaded, the changeover switch 17a connects the increaser circuit 13 to the current limiting circuit 15, and the dial knob 24 adjusts the exposure sensitivity according to the brand of film 7 to be used. Except for setting the exposure sensitivity setting circuit 16, the operation is exactly the same as described above.

In this case, the light is directly incident on the photoelectric conversion element 11, and an output proportional to the amount of exposure is generated, which becomes the output B in the same way as above, and after being converted from A to D, the same judgment is performed. In this case, the device operates as a kind of exposure meter in the photographing mode to check whether the exposure amount is correct or not.

Therefore, according to the present invention having the above configuration, the amount of light given to the film during exposure is directly measured from the amount of light transmitted through the film, and the exposure sensitivity and light transmittance of the film used are measured based on the amount of transmitted light. There is no more reliable way to confirm proper exposure than this, and it is possible to immediately know whether the shooting was successful or not at the end of the shooting process, and whether the exposure was successful or not. In such a case, you can immediately reselect the aperture and shutter speed and take the picture again, eliminating the mental burden of waiting for development. At the same time, you can prevent situations such as missing a photo opportunity, and take the photo again. You can definitely take photos with this.

Furthermore, according to the present invention, even when no film is loaded, it is possible to check whether the exposure amount is appropriate or not under the same conditions as during shooting, making it possible to carry out more complete and reliable photography. When not loaded, each judgment can be made with the same circuit configuration, so there is no wastage in the circuit configuration.Furthermore, the confirmation display can be retained, so there is no confirmation error, making it effective to use and easy to operate. It has many features such as:

[Brief explanation of drawings]

FIG. 1 is a block explanatory diagram showing one embodiment of the proper exposure confirmation device according to the present invention, and FIG. 2 is an external view showing the overall configuration of the same. 1 is the camera optical system, 2 is the lens system, 3 is the aperture mechanism, 4
1 is a shutter mechanism, 5 is a film holder, 6 is a partition plate, 7 is a film, 8 is a sliding lid, 9 is an insertion part, 1 is a control part, 11 is a photoelectric conversion element, 13 is an increaser circuit, 14 is a light transmission rate setting circuit, 15 is a current limiting circuit,! 6 is an exposure sensitivity setting circuit, 17 is a switching circuit, 18 is an A-D conversion circuit, 1
9 is a determination circuit, 20 is a display circuit, and 22 is a start circuit. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a camera using a film holder in which raw film loaded on the surface of a partition plate is shielded from the outside by a sliding lid that can be freely inserted and removed, an insertion section 9 that can be inserted into and removed from the back of the partition plate, and A photoelectric conversion element 11 is disposed in the insertion part corresponding to the position of the transparent window, and receives the light transmitted through the film during film exposure, and outputs a current proportional to the amount of transmitted light, and increases the detection power of the photoelectric conversion element 11. a light transmittance setting circuit 14 for setting an appropriate value of the amount of light transmitted through the film; a current limiting circuit 15 for limiting the output of the amplifying circuit; and the light transmittance setting circuit and the current limiting circuit. an exposure sensitivity setting circuit 16 for applying conditions to the film exposure sensitivity; an operation knob 24 for causing the light transmittance setting circuit and the exposure sensitivity setting circuit to set light transmittance and exposure sensitivity corresponding to the brand of film used; When loading the film with amplified output, the light transmittance setting circuit 1
4, and when the film is not loaded, the current limiting circuit 15
A change-over switch circuit 17 that switches to each of these, and an A-D converter circuit 18 that converts the output of these light transmittance setting circuits or current limiting circuits into digital values, and an A-D converter circuit 18 that converts the outputs of these light transmittance setting circuits or current limiting circuits into digital values. A determination circuit 19 determines whether there is a
A display circuit 20 that displays and holds the display in response to either proper or excessive conditions, and a start circuit 22 that has a start switch that discharges the residual voltage of the photoelectric conversion element and releases the display circuit. Appropriate exposure confirmation device for a camera, characterized by comprising: