JPS5929845B2 - Photography information display device for electric exposure camera using light emitting body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photographing information display device for an electric exposure camera that displays photographing information such as shutter speed and aperture value using a light emitting body.

Several display devices of this kind have been proposed in the past, but for example, taking a shutter speed display device as an example, a numerical value indicating the reciprocal of the shutter speed is displayed on a display board placed in the viewfinder (1000), 500), etc. ...1 and IE
Write down each V, place a light emitting device such as a light emitting diode (hereinafter abbreviated as LED) next to each value, and
One of the light emitters is selectively caused to emit light by a signal including shutter speed information from a photometry circuit,
The most common type is a type that displays the shutter speed by displaying the light emitting body.

However, when looking at electric exposure cameras today, exposure is performed automatically in this type of camera, so it is not necessarily necessary to display the shutter speed and aperture for each IEV, and for example, high brightness limit, low brightness limit, hand shake. It is often sufficient to display those values corresponding to three of the limits.

From this point of view, the above-mentioned conventional device has the disadvantage that it displays more than necessary and also increases the number of light emitters, leading to increased costs. Therefore, based on the above-mentioned viewpoint, an object of the present invention is to provide a photographing information display device for an electric exposure camera that can perform necessary and sufficient display using as few light emitters as possible. A plurality of first display symbols indicating limit exposure values/and at least one exposure value between these limit exposure values are illuminated by external light, while the other side is represented by an adjacent first display symbol. A plurality of light emitters each having a plurality of second display symbols respectively provided between adjacent first display symbols to represent an exposure value region between two exposure values. It is characterized by being configured to be illuminated by selective light emission. Embodiments of the present invention will be described below with reference to the drawings.

In the embodiments described below, this invention is applied to a shutter speed display device for a single-lens reflex camera, but as will be described later, the invention is of course not limited to the following embodiments. ~ First, Figures 1 to 5 show a first embodiment of the present invention, in which 1 represents a focusing plate of a camera, 2 represents a movable reflecting mirror, 3 represents a pentaprism, and 4 represents a condenser lens, which are not shown in the figures. Together with a photographing lens and an eyepiece that do not have the same function, they form an optical system for the viewfinder of a known single-lens reflex camera.

5a, 5b, and 5c are LEDs, each of which is fixed to the left side of the pentaprism 3 by an LED holder 6 integrated with the camera body (not shown), and selectively emits light in response to a shutter speed signal from a photometry circuit, which will be described later. .

Reference numeral 7 denotes a light guide for guiding the light emitted from the LEDs 5a, 5b, and 5c to the display panel 8, and as shown in the figure, there are three guide portions 71, 72 bent at right angles corresponding to each LED.
73 connected by connecting portions 74 and 75, and are actually integrally formed by molding, for example.

This light guide 7 is connected to each guide portion 7, 72, 73 by a light guide holder 9 which also serves to prevent external light that does not pass through the focusing plate 1 from entering the display panel 8.
is held so that its entrance surface is in contact with the LEDs 5a, 5b, and 5c, and the light emitted from each LED is reflected by the reflecting surfaces 7a, 7b of each guide portion and enters the display plate 8. Here, the display plate 8 is transparent and is fixed to the upper surface of the bent portion of the light guide 7 that enters between the pentaprism 3 and the condenser lens 4, and as best shown in FIG. 1000, H, 125, M, 30 in order from
, S, and 8S, and triangular symbols 8a, 8b, 8c, 8d, 8e, and 8f provided between the letters.
The portions of this display board marked with letters H, M, and S are the reflective surfaces 7b of each guide portion 71, 72, and 73, respectively.
, and each L reflected by the reflecting surface 7b
It is illuminated by light from the ED. Further, the display plate 8 is located on the focal plate 1 in a position where its image is outside the viewfinder field frame as shown in FIG.
5, 30, 8S and symbols 8a, 8b, 8c, 8d, 8e
, 8f pass through the photographic lens, are reflected by the reflecting mirror 2, are diffused by the focus plate 1, and are illuminated by external light that passes through the condenser lens 4. Some of that external light is
Although it also faces the reflective surface 7b of each guide portion 71, 72, 73,
In this embodiment, a portion of the light guide holder 9 covers its reflective surface 7b as shown in FIG. 2, so that light directed toward the reflective surface 7b does not enter the light guide. Therefore, the letters H, M, and S on the display board 8 are completely shielded from external light. In addition, the characters 100 on the display board 8
0 represents the high speed limit of 1/1000 seconds, 8S represents the low speed limit of 8 seconds, 30 represents the camera shake limit of 1/30 seconds, and 125 represents the medium speed of 1/125 seconds. However, the display contents of the remaining letters H, M, and S will be made clear in the explanation of the operation of this embodiment.

Next, the circuit configuration for selectively causing the LEDs 5a, 5b, and 5e to emit light in this embodiment is as shown in FIG.

In this figure, numeral 10 is a well-known photometry circuit that has a light receiving element that measures the light that has passed through the photographic lens, and at its output terminal there is a voltage that corresponds to the calculation results of the subject brightness, aperture value, and set film sensitivity. can get. R,, R2, R3, and R4 are comparison resistors connected in series to the constant current source 1, and their respective connection points A, b, c, and d have the resistance value of R1, and the resistance values of R, and R2. sum, sum of resistance values of Rl, R2, R3, R,,R
A voltage proportional to the sum of the resistance values of R2, R3, and R4 is obtained. Also, 11, 12, 13, Gin':. i': π嶌: Emma soil = pass cover ↑ μ side is connected to each connection point A, b, c, d of resistors Rl, R2, R3, R4, for example, taking the comparator circuit 11 as an example. , this comparison circuit 11 is the photometric circuit 1
When the output voltage of 0 is higher than the voltage at connection point a, a low level output is produced, and conversely, when the output voltage is higher than the voltage at connection point a, a high level output is produced.

Further, 15 is an oscillation circuit that generates a pulse signal with a constant period, 16 and 17 are NAND circuits, and the two input terminals of the NAND circuit 16 are connected to the comparator circuit 11 and the oscillation circuit 15, respectively.
One of the input terminals of the NAND circuit 17 is connected to the output terminal of the comparator circuit 14 via an inverter 18.
and the other is directly connected to the output terminal of the oscillation circuit 15.

Further, 19 and 20 are AND circuits, and the AND circuit 19 has two input terminals connected to the output terminals of the NAND circuit 16 and the comparison circuit 11, respectively. The output terminal of the comparison circuit 13 is connected to the output terminal of the NAND circuit 17, and the other input terminal is connected to the output terminal of the NAND circuit 17. The LEDs 5a and 5c are connected to the output ends of AND circuits 20 and 19, respectively.
The LED 5b is connected between the output terminals of the comparison circuits 12 and 13.

With the above configuration, when the subject brightness is extremely low and the exposure is controlled at a shutter speed outside the low speed limit, the outputs of the comparison circuits 11, 12, 13, and 14 will be as shown in FIG. All are at a high level.

Then, an alternating signal that becomes low level only when the output of the oscillation circuit 15 is high level is obtained at the output terminal of the NAND circuit 16, and a high level signal is obtained in the AND circuit 19 only when the output of the oscillation circuit 15 is high level. Since this is obtained, the LED 5c repeats blinking and periodically illuminates the letter S on the display board 8. On the other hand, since the output of the comparison circuit 14 is converted to a low level by the inverter 18, a constant high level signal is obtained at the output terminal of the NAND circuit 17, while a low level signal is obtained at the inverter 21. Therefore, the LED 5a does not light up at all. Furthermore, since high-level signals are applied to both ends of the LED 5b, the LED 5b also does not light up at all.

That is, in this case, only the LED 5c repeatedly flashes, illuminating the letter S, and displaying in the viewfinder that the shutter speed will be longer than the low speed limit. Next, when the shutter speed is faster than the low speed limit but slower than the camera shake limit, only the output of the comparison circuit 11 becomes a low level as shown in FIG.

Then, since a high level signal is always obtained at the output terminal of the NAND circuit 16, the LED 5c continues to light up and the letter S is displayed.
to illuminate. On the other hand, the LEDs 5a and 5b do not light up at all because the conditions are the same as when the vehicle is outside the low speed limit. In addition, in the case of a medium speed region where the shutter speed is faster than the camera shake limit but slower than the medium speed of 1/125 seconds, the outputs of comparison circuits 11 and 12 are at a low level, and the outputs of comparison circuits 13 and 14 are at a high level. become.

Then, since the AND circuits 19 and 20 output low level outputs, the LEDs 5a and 5c do not light up at all, but since high and low level signals are always applied to both ends of the LED 5b, it continues to light up and illuminates the letter M. Also, the shutter speed is 1/
In the high speed region between 125 seconds and 1/1000 seconds, only the output of the comparison circuit 14 becomes high level.

Then, LEDs 5b and 5c do not light up at all, but the AND
Since the output of the circuit 20 is always at a high level, the LED 5a
continues to light up, illuminating the letter H. Furthermore, since the subject brightness is too high, the shutter speed is 1/1/2, which is the high speed limit.
If it becomes faster than 1000 seconds, the comparison circuit 11,
The outputs of 12, 13, and 14 all go to low level.

Then, LEDs 5b and 5c do not light up because the conditions are the same as in the high-speed region, but since an alternating signal that becomes low level only when the output of the oscillation circuit 15 is high level is obtained at the output terminal of the NAND circuit 17, LED 5a repeatedly blinks periodically, illuminating the letter H. Thus, in this example,
Three LEDs were used to display the shutter speed in 1/125 seconds at medium speed, but it still emitted far more light than the conventional device, which used a luminous body to display each EV. It has the advantage of being able to reduce the number of bodies and being extremely cheap in terms of cost. And the letter H. By blinking and lighting the letter "S" and lighting the letter "M", a total of five levels of display can be achieved as shown in FIG. 6, and the device satisfactorily functions as a shutter speed display device for electric exposure force cameras.
Next, FIGS. 7 to 9 show that on the display board 208,
Patterns 208a, 208b, 208c as shown in the figure
The letters 1000, 125, 3 indicate the speed series
0 and 8S, and these patterns are connected to LED5a,
While illuminating with the light emitted from 5b and 5c, the reflective surface 207b at the tip of each light guide 2071, 2072, 2073
A second stair surface 207c of the present invention is provided adjacent to the stair surface 207c through which external light from below can pass, and characters 1000, 125, 30, and 8S are illuminated by the external light that has passed through the stair surface. An example is shown.

Here, a light shielding member 209 is attached to the reflective surface 207b, and external light from the focus plate toward the patterns 208a, 208b, and 208c is reflected or absorbed by the light shielding member 209. Furthermore, since the light emitted from the LED is generally red, the display board 208 is colored green, which is a complementary color to red, except for the character series and patterns 208a, 208b, and 208c that indicate the shirt speed. When the LED flashes or lights up, the illuminated letters H, M, and S appear more clearly in the view of the viewfinder. In addition, when using the display board 208 like this embodiment, each guide part 2071, 2072, 2073 has a staircase surface 207.
It is not necessarily necessary to provide a light shielding member 209 or attach a light shielding member 209 to the reflective surface 207b. For example, if the configuration is as shown in FIG. The characters shown are illuminated by external light and become visible.

That is, in FIG. 10, the reflective surface 207b of the light guide 207 corresponds to the patterns 208a, 2
It is located directly below 08b and 208c, and this reflective surface 2
The diffused light from the focus plate 1 that has entered the focus plate 07b is refracted to the outside of the focus plate 1 and the optical path. Therefore, even if the patterns 208a, 208b, and 208c are illuminated by the light, these patterns will not appear in the viewfinder's field of view, and the patterns illuminated by the light from the LED and the LED
There is no risk of misidentifying the pattern with a pattern that is not illuminated by the light from the outside. Furthermore, FIGS. 11 and 12 show various display boards. The display board 308 in FIG. 11 has punched parts 308a and 308b corresponding to the letters H and M, respectively, and also has a shutter speed series. The letter shown and the letter S are colorless and transparent, and the other parts are transparent and colored green.

If the pattern displaying the medium-high speed range is just letters, even when illuminated with light from the LED, the view of the viewfinder is bright, making it somewhat difficult to see, but with this display board, the L
Since the light from the ED passes through the punched parts 308a and 308b and directly enters the eye, the punched parts 308a and 308b can be clearly observed even if the field of view of the viewfinder is bright. Note that if the subject is dark, the viewfinder field of view will also be dark, making it difficult to see the letters indicating the shutter speed series, so set SLOW so that you can clearly see that the shutter speed is outside the camera shake limit or low speed limit. Displayed with the letter S. On the other hand, the display board 408 in FIG.
Colorless light-diffusing circle portions 408a, 408b, and 408c are provided around the letters H, M, and S, and the remaining portions are transparent and colored green.

In this way, the circle portions 408a, 408b, 4
Because 08c appears to be colored red by the light from the LED,
The letters H, M, and S become very easy to observe. Another feature of this display board 408 is that the letters 8S indicating the slow shutter speed can be seen above the viewfinder, so that the letters 8S and 8S indicating the slow shutter speed are visible. M. The arrangement of S is upside down.

This is because, in general, when the camera is held in a horizontal position, a bright part of the sky appears above the viewfinder, and for example, when the letter H appears above as in the first embodiment of this invention, the bright part of the sky appears. This is to prevent the letters H from overlapping and becoming difficult to see unless a large current is applied to the LED VC to increase the amount of light emitted.

In other words, with this display board 408, the letter S lights up or blinks when the subject brightness is low, and even if the sky appears to overlap behind the letter S, it is because the sky itself is dark. , the letter S will be clearly visible. On the other hand, even in the case of a high-brightness subject where the letter H lights up or flashes, dark subjects such as the ground are often visible in the lower part of the viewfinder's field of view, so the letter H is often clearly visible. It turns out. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments as described above, and can be applied to, for example, electric exposure power cameras other than single-lens reflex cameras.

Further, in a shutter speed priority aperture EE camera, an aperture value can be displayed as an exposure value, in which case the high brightness side limit exposure value represents the minimum aperture value, and the low brightness side limit exposure value represents the open aperture value. Furthermore, the limit exposure value, the exposure values obtained by dividing the limit exposure value, and the exposure value area sandwiched between these exposure values can be indicated by letters, patterns, punched parts, or various other display symbols. As described above, in the display device of the present invention, the optical system displays a plurality of first display symbols indicating the limit exposure values on the low brightness side and the high brightness side and at least one exposure value between the limit exposure values. While illuminating with external light passing through, a plurality of second display symbols are provided between adjacent first display symbols, and a plurality of light emitters provided corresponding to the second display symbols are illuminated by the subject brightness and preset. The display symbol is illuminated by selectively emitting light according to the value of the exposed exposure factor. Since the exposure value range between the exposure values indicated by the display symbols is displayed, the number of light emitters is greatly reduced compared to conventional display devices in which all display symbols are illuminated by light emitters. This has the advantage of lower manufacturing costs.

Furthermore, the display device of the present invention can fulfill its necessary and sufficient role as an exposure display device for an electric exposure power camera by displaying an exposure value region sandwiched between the exposure values indicated by adjacent first display symbols. It is extremely rational.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention, FIG. 1 is a plan view of the main part, FIG. 2 is a sectional view of the main part, FIG. 3 is a perspective view of the main part, and FIG. 4 is a perspective view of the main part. Figure 5 shows one view of the viewfinder.
The figure is an electric circuit diagram, and FIG. 6 is a table showing the relationship between the shutter speed, the output of the comparator circuit, and the blinking state of the LED.

Claims (1)

[Claims] 1. A plurality of first display symbols indicating limit exposure values on the low-brightness and high-brightness sides and at least one exposure value between these limit exposure values, and two display symbols represented by adjacent first display symbols. A plurality of second display symbols provided between adjacent first display symbols and all of the first display symbols are illuminated with external light so as to represent an exposure value region between the exposure values. a plurality of light emitters for illuminating second display symbols provided corresponding to each of the second display symbols; Accordingly, it is determined to which of the exposure value regions represented by the second display symbol the adaptive exposure value belongs, and the adaptive exposure value is provided corresponding to the second display symbol representing the exposure value region to which the appropriate exposure value belongs. A photographing information display device for an electric exposure camera, comprising a circuit for selectively causing a light emitting body to emit light.