JPS59114522A - Camera with exposure mode switching device - Google Patents

Abstract

PURPOSE:To make easily a person not familiar with photographing possible to photograph by selecting a photometric mode of a camera suitable for an exposure mode in accordance with a set exposure mode. CONSTITUTION:Photoreceptor elements 8 (8a-8e) are divided correspondingly to the light measuring section patterns a-e of a focussing plate 3 and a logarithmic compression diode LD and light measuring high-input impedance operational amplifier OP1 are installed for logarithmically compressing the photoelectric current of analog gates Ga-Ge for switching the photoreceptor elements 8 and the photoreceptor elements 8. Light measuring information obtained by logarithmically compressing the photoelectric current produced by the photoreceptor elements 8 is outputted to the output of the operational amplifier OP1. The light measuring information, information set by an exposure information setting circuit IFS, and exposure level correcting information are calculated at another operational amplifier OP2 through operational resistances R4-R9 and the output of the amplifier OP2 is added to a well known exposure controlling circuit CKT, and thus, the exposure is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera having an exposure mode switching device that performs photometry switching in response to exposure mode switching.

Conventionally, the exposure mode switching device was in aperture priority mode.

It is possible to switch between a shutter priority mode, a program mode, etc., and recently there have been an increase in the number of programs such as a shutter priority magic mode, an aperture priority magic mode, etc.

In addition, the metering method is center-weighted metering and average metering.

It has become extremely convenient for photographers, as they can choose between partial metering and spot metering, depending on their preference.

However, while it has become convenient to be able to switch modes in this way, it is complicated to operate for beginners, and there are many cases where users do not know how to use it and use it incorrectly.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to set a photometry mode setting circuit according to an exposure mode switching operation, and to switch a photometry range switching circuit according to the setting of this photometry mode setting circuit. It is an object of the present invention to provide a camera having a switching device.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows a program diagram for each exposure mode of the camera. In Figure 1, the vertical axis is the aperture value (FNO).
, the horizontal axis shows the shutter speed α), and the diagonal axis shows the EV value.

① is a normal program exposure control line and is called normal mode. ■ is the open F value of the photographic lens, F2, and the shutter speed is 1710 along the horizontal axis according to the subject brightness.
The aperture value changes up to 00 seconds, and the aperture value changes at 1/1000 seconds. F2 is called shallow focus mode because it is suitable for taking photos with shallow depth and is suitable for model photography. Also, 1710
The area where the aperture υ changes from 00 seconds is suitable for fast-moving subjects and is called the stop-motion area. In addition, ■ is a program that prioritizes filtering of filtering file. That is, F
The shutter speed changes with il, and at the point where it intersects the normal mode line, where the 9BV value is large, the mode becomes normal mode. In such a case, the image has an aperture value of F'
Since it is ll, the photo has a lot of depth. This mode is called the pan focus mode. In case (2), the shutter speed initially changes with priority given to the aperture of F2, but from the point of F60, the aperture value changes with priority given to the shutter, and when it reaches F22, the shutter speed changes and becomes larger. In such a case, when photographing a fast-moving subject, you can take a panning shot, resulting in an elegant photograph. This mode is called the shooting shot mode.

In the present invention, we have considered what kind of photometry mode is optimal for each of these exposure modes, and the results are as follows.

■In normal mode, average metering is suitable for general photography.

In the shallow focus mode or stop motion mode (2), partial metering is suitable in order to position the main subject in the center of the finder screen and make the periphery of the finder screen less noticeable.

In the pan focus mode (2), the condition is that the focus is even across the entire surface, and it is necessary that the exposure is average across the entire screen without emphasizing any part of the image. , average metering is suitable.

The ◎ panning shot mode uses a shooting technique called panning. Therefore, since the camera is generally moved sideways on the screen, it is appropriate to measure the light in a strip across the screen.

Here, FIG. 2 shows the optical configuration of the camera, where 1 is a photographing lens, 2 is a movable mirror, 3 is a bottle plate, 4 is a condenser lens, 5 is a pentaprism, and 6 is an eyepiece lens. Therefore, the light that has passed through the photographic lens 1 is reflected by the mirror 2, and the focusing plate 3. The image passes through a condenser lens 4, is reflected by a pentaprism 5, and is visually recognized by an eyepiece lens 6. The focusing plate 3 is made of an electrical optical diffuser, for example, a liquid crystal, and is divided into appropriate patterns as shown in FIG. 3, and is constructed so that a voltage can be applied separately to each division by an individual electrode.

The concentration changes in each section by applying a pulse voltage. 7 is a liquid crystal drive circuit, 8 is a light receiving element, and 012 is a condensing lens in front of the light receiving element. For example, in Figure 3, if you lower the voltage at the point a on the focusing plate 3 to increase transparency, and increase the voltage to lower the transparency in other areas, the light receiving element 8 will have partial photometry that measures the area a. .

Therefore, such partial photometry is used in shallow focus mode and stop motion mode.

Furthermore, if the entire surface of the focusing plate 3 in FIG. 3 is made uniform in illuminance, average photometry will be obtained. Normal mode.

? (When in focus mode, average light metering is used.

Furthermore, increase the transparency of d, a, and e of focus glass 3,
If the transparency of other parts is reduced, band-shaped metering becomes 5'l, and band-shaped metering is used in vanning shot mode. 9 is a control circuit to which the output of the light receiving element 8 is input. By making the pattern of the light receiving element 8 similar to the liquid crystal pattern of the photometry section, the photometry range can be displayed. 10 is a mode switching circuit, and 11 is a mode setting circuit.

FIG. 4 shows light receiving elements 8 (8a, 8b, 8c).

8d and 8e) and the shape of the liquid crystal pattern displayed by the photometry section of the focusing plate 3 are similar in shape, and the drive circuit for the light receiving element 8 and the liquid crystal focusing plate 3 is shown. Since the pattern shape of the light receiving element 8 and the shape of the photometric display pattern of the liquid crystal focusing plate 3 are similar, the photometric part can be displayed with a slight difference in density of the liquid crystal of the focusing plate, and the focusing plate does not even become visible. The light-receiving elements 8 (8a to 8e) are divided into p, Ga-
Ge is an analog gate for switching the photodetector, CD is a logarithmic compression diode for logarithmically compressing the photocurrent of the photodetector,
OP.

is a high input impedance operational amplifier for photometry, and the output of this operational amplifier is photometry information obtained by logarithmically compressing the photocurrent generated by the light receiving element 8. This photometric information, the information set by the exposure information setting circuit FS, and the exposure level correction information are calculated by the operational amplifier OP via the operational resistors R4 to R9. operational amplifier OP
.

The output is applied to a known exposure amount control circuit OKT to control exposure. Tri-Tz3 is a switching transistor for inputting exposure level correction information, and is switched in conjunction with exposure mode setting. KVc, V
c is a reference power supply, and Vcc is a power supply voltage. swt, sw
n and swm are switches linked to an exposure mode setting member (not shown), swl is a switch that is turned on in normal mode and pan focus mode, swn is a switch that is turned on in shallow focus mode and stop motion mode, and swm is a vanning switch. The light-receiving element and the liquid crystal pattern are selected via the switch l) turned on in the shot mode, the pull-down resistors R1 to R3, the OR gates ORI to OR3, and the inverters IN to IN. The electrodes corresponding to e are a1 to e,
When a high voltage is applied to S, a, a, to e, the incident light is scattered and the transparency is reduced.Next, the operation of the above structure will be explained. When the exposure mode setting member is set to normal mode or pan focus mode, switch SW■ turns on.
Switch SW■ and switch SWn[ remain off.

When the switch SW2 is turned on, the power supply voltage Vcc is applied to the OR gates "OR" to "OR" and the transistor Tri. Therefore, the transistor Tri is turned on and the respective OR gates "OR" and "OR" are turned on.

The output of OR5 becomes high level. The high level signals of these OR gates OR, to OEL are connected to the inverter I.
Since a high voltage is not applied to the liquid crystal focusing plate 3, the liquid crystal focusing plate 3 is completely transparent and indicates that full-scale photometry is being performed. at the same time,
The no-y level signal of each OR gate OR, to OR, turns on all the analog gates Ga to Ge, and the light-receiving element 8a
The entire surface is photometered at 8e to 8e. These light receiving elements 8a to 8
Photometric information obtained by logarithmically compressing the photocurrent generated by e is generated from the output of the operational amplifier OP. It is operated by an operational amplifier OP via R,4,R,,R,,R,. Operational amplifier O
The output of P is applied to the exposure control circuit OKT, which performs exposure control based on the output of the operational amplifier OP.

■ When the exposure mode setting member (not shown) is set to shallow focus mode or stop motion mode, switch SW■ turns on, and switch SWI and switch SW
■ remains off. When the switch SW2 is turned on, the power supply voltage Vcc is applied to the OR gate 0FLI and the transistor Tr3. For this reason, the transistor Tr
3 is turned on, only the output of the OR gate OR1 becomes high level. This high level signal of ORI is applied to the inverter IN, so a high voltage is applied to the bI+ cIe 'Is eI terminal of the liquid crystal focusing plate 3, and the
The transparency of the LCD panel 3 decreases, a low voltage is applied to only one terminal a of the liquid crystal focusing plate 3, and only the terminal a of the liquid crystal focusing plate 3 is transparent, indicating that partial photometry is being performed. At the same time, the high level signal of OR game turns on the analog gate Ga, and the light is measured by the light receiving element 8a. The photometric information obtained by logarithmically compressing the photocurrent generated by these light receiving elements 8a is sent to the operational amplifier O.
The photometric information from the operational amplifier OP, the information set by the exposure information setting circuit IFS, and the exposure level compensation R,,R, generated from the output of P,
, R, , R, is operated by the operational amplifier OP. The output of this operational amplifier OP2 is the exposure amount control circuit OK.
The exposure control circuit OKT is added to the operational amplifier OP.
Exposure control is performed based on the output of .

(2) When an exposure mode setting member (not shown) is set to the vanning shot mode, the switch 5WlII is turned on, and the switches SWI and SwII remain off. This switch SWl [when the switch SWl is turned on, the power supply voltage Vcc is ON or OFF] OR.

It is added to OR4, OR, and transistor Tr2.

Therefore, the transistor Tr2 is turned on, and the outputs of the OR gates OR, , OR4, and 0R11 become high level.

The high level signal of OR4, OR, is sent to the inverter IN.

Since it is added to IN, , IN6, b of the LCD focusing plate 3
Ie A high voltage is applied to the C+ terminal, and the transparency of the liquid crystal focusing plate 3 is reduced, and the liquid crystal focusing plate 3 becomes transparent. B, d, and e of plate 3 are transparent and indicate that strip photometry is used.At the same time, the no-i level signals of each OR gate OR,,OR4,0RIl are analog gates).Ga, αl, Ge are turned on and light is received. The central strip is photometered by the elements 8a, 8d, and 8e. Photometric information obtained by logarithmically compressing the photocurrent generated by these light receiving elements 8a, 8d, and 8e is generated from the output of the operational amplifier OP. The photometric information and exposure information setting circuit IFS, the information set by the positive and exposure level supplementary resistors are connected to the operational amplifier o via R4, Ra, Rs, and Re.
Calculated in pt. The output of this operational amplifier OP is added to the exposure control circuit 0KTK, and the output of the operational amplifier OP is added to the exposure control circuit OKT.
performs exposure control based on the output of operational amplifier OP.

In place of the liquid crystal focusing plate of the above embodiment, the present invention uses a sub-mirror 13 to reflect the light that has passed through the partially transmitting part of the mirror 2 as shown in FIG.
For partial photometry, the pentaprism 5
A cylindrical lens 16 is placed behind and in front of the light receiving element 15 to reduce the vertical direction of the image, and when the cylindrical lens 16 is removed from the optical path, it measures average light, and when it is inserted, it measures band-shaped light as shown in Figure 6. Become. By switching these in conjunction with the exposure mode setting member, it is possible to achieve photometry switching according to the exposure mode. Also, JP-A-57-
If the exposure mode is displayed as a picture as in No. 78033, the multi-mode selection as in the present invention can be easily understood, resulting in good operability. Furthermore, if the metering method can be selected manually, shallow focus,
In stop motion mode, only partial metering can be selected, in vertical, normal, and pan focus modes, only average metering can be selected, and in panning shot mode, only strip metering can be selected. It is also possible to do something that is prohibited. As detailed above, according to the present invention, by making it possible to select the camera's metering mode suitable for the exposure mode according to the exposure mode setting, it is no longer necessary to take the trouble of considering the metering mode appropriate for the exposure mode. This has the advantage that even people who are not good at photography can easily take pictures.

[Brief explanation of the drawing]

Fig. 1 is a program diagram for each exposure mode of the camera according to the present invention, Fig. 2 is an optical configuration diagram of the camera showing an embodiment of the present invention, and Fig. 3 is a diagram of the liquid crystal focusing plate shown in Fig. 2. 4 is a control circuit diagram of the camera shown in FIG.
The figure is an optical configuration diagram of a camera showing another embodiment of the present invention.
FIG. 6 is a diagram showing the photometry range of the camera shown in FIG. 5 during band-like photometry. 3... Liquid crystal focus plate, 8... Light receiving element 9...
Control circuit, 10...Mode switching circuit 11...Setting circuit-1111

Claims (1)

[Claims] The side light mode setting circuit is set in response to the exposure mode switching operation, and the light metering range switching circuit is switched in accordance with the setting of the light metering mode setting circuit, thereby adjusting the light output mode to suit the exposure mode. A camera having an exposure mode switching device, characterized in that the photometry mode of the camera can be selected.