JPS6070428A - Dimmable distance range display device of flash device - Google Patents

Abstract

PURPOSE:To determine exactly a dimmable distance range based on the latitude of a film, and to display it quickly and exactly by providing a means for detecting a diaphragm value of a photographic lens, an exposing area of the film, and a film sensitivity value, etc. CONSTITUTION:A diaphragm value Av from a diaphragm value output device 12 of a lens is stored in an RAM of a CPU 10. When a film cartridge 1 is inserted into a cartridge containing chamber 5, a code pattern 3 contacts a contact 6, is detected, and a film sensitivity value Sv from a film sensitivity output device 13 and an exposing area DELTASv from an exposing area output device 14 are also stored in the RAM. In a CPU 10, the maximum dimming distance and the minimum dimming distance are calculated from the maximum and the minimum dimmable guide numbers of an automatic dimming type flash device not shown in the figure, which are set and stored in an ROM in advance, and storage information of the RAM, and displayed on a display part 16 by a display control device 15. In this way, a usable range of the flash device is expanded, and a flash photographing causing no failure can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a photographing distance range display device that can accurately display the dimmable photographing distance range of a dimmable flash device.

[Background of the invention]

An automatic flash device, which is generally classified as an auto strobe device, illuminates a subject with light from a discharge lamp that is emitted in synchronization with the shutter operation of the camera, and receives the reflected light from the subject with a light-receiving element. It is configured to integrate the photoelectric output of the light receiving element and to stop emitting light when its output reaches a predetermined value (that is, an appropriate exposure amount). The photoelectric output of this light-receiving element is proportional to the reflectance of the subject and inversely proportional to the square of the distance to the subject. By the way, the reflectance of a standard subject is said to be between 3% and 90%. A typical photographic film has a latitude that can sufficiently cover this range of reflectance. Therefore, when setting the aperture, etc., the exposure amount is based on the sensitivity of the film used, and when setting the aperture, etc., the exposure is set to 1 step (Ev 1 step), which gives +1 to +3 steps overexposure or -1 step anoder exposure on negative film. However, the actual photographs obtained are almost the same as those with proper exposure. Mata,
With color reversal film, even if there is an exposure error up to ±() and 5 steps, good results can be expected in actual photographs. In recent years, film cassettes have been commercially available in which exposure ranges in which good photographic results can be expected are coded together with film sensitivity based on latitudes that vary depending on the type of film.

On the other hand, in automatic flash devices, the photoelectric output of the light receiving element is inversely proportional to the square of the distance to the subject, so when photographing the same subject using flash lighting, the distance between the subject and the discharge lamp is short. Then, immediately after the discharge lamp emits light, a light emission stop signal is output. However, in this case, by the time the discharge lamp stops emitting light due to delays in the circuit system, etc.
It will take some time. When the subject is close, the delay time becomes too large to ignore compared to the required irradiation time, and the amount of light incident on the film surface greatly exceeds the appropriate exposure amount. There was a tendency to produce overexposed photographs.

In addition, among the guide numbers that practically indicate the light intensity of the light source of an automatic flash device, it is calculated from the maximum guide number, which represents the maximum light output at full flash without stopping the flash, and the lens aperture darkness. If the subject is located at a distance greater than the subject distance set, the light emission stop signal is not output and the discharge lamp emits full light. However, the amount of light reaching the film surface is less than the appropriate amount of light, resulting in an underexposed photograph.

Therefore, as a means to solve the above-mentioned drawbacks of overexposure and underexposure in auto-adjustable flash devices, there are two methods: 1) Proper exposure using flash illumination can be determined from subject distance information determined by the distance adjustment ring on the lens barrel. 2) A method of determining whether or not a suitable exposure can be obtained by pre-emitting a discharge lamp before taking a picture and measuring the reflected scene. 3) A method of detecting that a light emission stop signal for interrupting light emission of a discharge lamp is not output when the subject is far away, and flashing an indicator light to display a warning are conventionally known.

However, these solutions all judge whether or not the exposure is appropriate based on a guide number based on the displayed film sensitivity, and set the exposure range based on the latitude, which differs depending on the type of film, as the judgment standard. It's not something I have.

Therefore, even if a negative determination is displayed using the conventional means described above,
- In general, it is not always possible to obtain photographs with inappropriate exposure.

Moreover, if the determination is negative, the exposure error is not displayed, so if the determination is ignored and the photograph is taken, there is a risk that the photograph will be improperly exposed. Furthermore, if the above-mentioned known means is followed, there is no danger of the photograph being improperly exposed, but since the judgment standard range is narrower than the shooting distance range that will substantially produce good photographs, the range of use of the flash device will be narrowed. In some cases, there is a risk of missing a photo opportunity.

[Purpose of the invention]

In view of the above-mentioned circumstances in the conventional device, the present invention provides an auto-adjustable flash device with a dimmable distance range display that can accurately determine the dimmable distance range based on the latitude of the film and quickly and accurately display the dimmable distance range. The purpose is to provide equipment.

[Summary of the invention]

In order to achieve the above object, the present invention has a central aperture device (center output device) for fully detecting one aperture aperture of a photographic lens;
film information detection means for detecting at least an exposure range representing the latitude of the film and a film sensitivity from the information code; a first aperture aperture detected by the rain detection means;
From the film sensitivity 1st shift, P3 and exposure range, and the maximum guide number (large exposure amount) and minimum guide number (minimum exposure amount) of the flash device used, the maximum V @ original distance power) to the minimum alA 1 element Possible range of distance to key? and display means for displaying the dimming distance range calculated by the computing means, and the display means allows the film to be loaded to be passed through substantially the entire dimming distance range. The technical point is to configure it so that it can be displayed.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a film cartridge provided with known film information used in an embodiment of the present invention.
A code pattern 3 representing film information such as film sensitivity, exposure range representing latitude, and standard number of shots of the film 2 housed in the film 2 according to whether it is electrically conductive or non-conductive.
is provided.

FIG. 2 is a perspective view showing the film accommodating section of a camera that accommodates the film cartridge 1 having the code pattern 3 shown in FIG.
A plurality of electrical contacts 6 are provided in the cartridge storage chamber 5 for reading film information by making contact with the coat pattern 3 (see FIG. 1) provided on the film cartridge 1.
is provided, so that when the film cartridge 1 is inserted into the storage chamber 5, various film information can be read depending on which of the plurality of contacts 6 current flows through or not through the code putter 3. It is composed of

FIG. 3 is a block diagram showing an embodiment of the present invention.
A central processing unit (hereinafter simply referred to as r(, PUJ
It is abbreviated as. ) 10 inputs and outputs data via the bus 11, and the aperture information of the photographing lens (not shown) is
Aperture (outputted from direct output device 12 to bus 11. Second
Of the film information detected by the contacts 6 in the figure, film sensitivity information and exposure range information are output to the bus 11 from a film sensitivity output device 13 and an exposure range output device 14, respectively. Aperture 1 direct A v s Film sensitivity 1 output from these output devices 12, 13, 14 to bus 11
Direct Sv and exposure range ΔSv are input to CPU10,
The maximum guide number QNmaX of the flash device, which is stored and set in advance in the ROM in the CPUIO, and the minimum guide number QNm i representing the minimum amount of light that can be dimmed.
It is calculated together with n in CPU10. The result is output to the display control device 15 via the bus 11, and the display section 16, which includes display elements LED, to LED+o, such as light emitting diodes whose lighting is controlled by the display control device t15, displays a dimming range. It is configured to display time information.

FIG. 4 is a plan view showing the display unit 16 (1-) in FIG. Each display window 18 has a numerical symbol 19 indicating the distance.The display board 17 is provided on the back cover (not shown) of the camera body 4, and is connected to light emitting diodes LmDI~L, ED from the outside.
,. For example, if the dimmable distance range is 1.5 m to 11 m, the light emitting diodes are controlled so that 8 light emitting diodes from L E D2 to L E Ds+ are lit. Ru.

Next, the operation of the embodiment shown in FIGS. 2 and 3 will be explained according to the flowchart shown in FIG.

First, the aperture 1 aperture AV set by the aperture ring or automatic aperture adjustment device of the photographic lens (not shown) and output from the aperture direct output device 12 is input to the CPUIO (7) RAM (step 101). be remembered. Next, as shown in FIG. 2, after inserting the film cartridge 1 into the cartridge storage chamber 5 of the camera body 4 and loading the film,
When the back cover of the camera is closed, the contact 6 comes into contact with the code pattern 3 of the film cartridge I (see Figure 1), and the film sensitivity is detected by the contact 6 and output from the film sensitivity output device 13. ! : Sv
is stored in the CPU 10 (7) RA MR: Input (step l tl 2 )c'7'L-At. In addition, the exposure jW△Sv detected by the contact 6 and output from the exposure range output device iZl4 is also output from the RAI of the CPUI O.
It is manually input to the VI (Step 10: C), and this is also stored.

Here, CPU l (l is smooth jimelt OM
The maximum guide number GNmax of the 111t-type flash device, the minimum dimmable guide number QNmin, and the aperture 1 straight A V% film sensitivity 1 stored in the above-mentioned RAM. Direct SV%) The maximum dimming distance pmax is divided from the film information such as the exposure range Δsv of the film (step 1o4), and then the minimum dimming distance Dmin is calculated (step 105).
) to be done. For example, the maximum guide F of an auto-adjustable flash device
+ 7 bar GNmax (corresponds to the guide number aN+ of a normal flash) is 32 at 15O100, the minimum guide number 〇Nmax is 8, aperture] direct AV is F'
=4. Roughly, the exposure range of the film △S v
Assuming that there are two steps on the over side and one step on the under side, the maximum distance at which a good photograph can be taken is one step on the anchor side, that is, 1 step.

This corresponds to the same direct guide number 32 X - Fi = 45 when using a film of 200. Therefore, the maximum shooting distance 1) max is 1) max =
45÷4ki11, (m). In addition, the minimum distance is the same as when using the two stages on the over side, that is, lSO2,5 film (direct guide number 8 ÷ (VΣ)" =
4 Tof, Zru.

Therefore, the minimum shooting distance Dmin is 1) min=4÷4=l (yn) becomes.

Maximum shooting distance calculated in this way 1) max=1
1 m and the minimum shooting distance 1) min = l rn are output to the display control device 15 and displayed on the display unit 16 (step 1 (16). In this case, the LED.

The light-emitting diodes from (1) to (1) light up to display the dimmable distance range that will allow you to take good photographs.

By the way, if you use an automatic flash device 4 that has the same maximum and minimum guide numbers as those in the above example, and set the aperture of the photographic lens to IIE' (rF = 4), the flash will be adjusted using the conventional calculation method. Calculating the range is as follows.

That is, -, the maximum distance that can be used for 11 lights 1) max is l
) max = 3274 = 8 Cm), which is 3 m closer than the previous embodiment of the present invention, and the minimum dimmable distance 1) min is Dmin = 3 ÷ 2-2-2 C, which is 3 m closer than the above-mentioned embodiment of the present invention. It is 1 meter further away than the example. Therefore, it is clear that when photographing according to the static display of the conventional device, the photographing range is narrowed, and there is a risk that possible photographing may actually be abandoned.

In the embodiment shown in FIG. 3 above, the flash device is built into the camera or used exclusively for the camera, and the maximum and minimum guide numbers of the flash device are determined by cPUl.

However, if a commercially available auto-adjustable flash device is used, a keyboard for inputting the maximum and minimum guide numbers may be added to the CPU10. In addition, instead of the keyboard, the flash device is equipped with a sensing code that represents the maximum and minimum guide numbers.
The flash device may be configured to be stored in 1ζAiVII of the CPU I O when the flash device is attached to the camera. In addition, in the embodiment shown in Fig. 3, the flash device is of an automatic light control type that interrupts flash emission by receiving reflected light, but if the subject distance is set on the camera side, the flash will emit light according to the subject distance. A dimmable flash device with controlled amount may also be used. Furthermore, the display unit 16 for displaying the dimming distance range includes light emitting diodes LEDs, ~LED, O'e.
However, using electro-optical display elements such as liquid crystals or electrochromic devices.

It may also be configured to display directly in numbers or the like.

〔Effect of the invention〕

As described above, according to the present invention, self-ii! The range of distances that can be photographed using the flash illumination of a dimmable flash device is automatically displayed according to the exposure range of the film loaded in the camera, so the range of use of the flash device can be increased. Not only is the image enlarged, but flash photography can be performed without failure.

[Explanation of symbols of main parts]

l...Film Patrone 3...
...Turn on the court no. O...CPU 10B...Calculation means 12...Aperture [direct output device (diaphragm 1 side detection means) output jt, ra input Watari, agent of Nippon Gengaku Kogyo Co., Ltd.
Takashi Bebe Male 72 Diagram O〈Renro-h4 Xi

Claims (1)

[Claims] an aperture one-direction detection device for detecting the aperture adjustment of a photographic lens; and a film information detection means for detecting at least a film sensitivity adjustment and an exposure range representing film latitude from a film information code provided on a film cartridge loaded in the camera. ; From the maximum and minimum kite number of the flash device used, one aperture, one film sensitivity, and exposure range detected by the rain detection means, the maximum dimming distance is calculated from the maximum dimming distance. A dimmable distance range display device for a flash device, comprising: a calculation means for calculating a dimming distance range by force; and a display means for displaying the dimming distance range calculated by the calculation means. .