JPH07306447A - Finder device for camera - Google Patents

Abstract

PURPOSE:To provide a finder device for a camera capable of suitably using plural driving systems in accordance with the contents of a display and further, arranging the display parts of both driving systems on one liquid crystal element CONSTITUTION:A visual field frame display part 411, an AF target mark display part 413, an in-finder information display part, 412 and an imprinting display part 414 are provided on one liquid crystal element, the visual field frame display part 411 is driven by a static driving circuit 56 and the AF target mark display part 413, the in-finder information display part 412 and the imprinting display part 414 are driven by a dynamic driving circuit 55.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder device for a camera in which a field frame or the like can be visually recognized by a liquid crystal element.

[0002]

2. Description of the Related Art Conventionally, various types of finder devices for displaying a photographing range of a subject have been developed and adopted.
Among them is a bright frame finder that displays the shooting range with a bright frame. In the daylighting method, which is one of the methods for displaying the bright frame, a display plate with a transparent field frame is provided outside the finder optical path, and external light is made incident on the display plate through a daylighting window provided on the top surface of the camera or the like. Then, the light transmitted through the field frame is made incident on the finder optical path, thereby displaying the field frame in the finder.

[0003]

The bright frame finder is required to have high transparency because the frame becomes difficult to see if there is a small amount of external light entering through the daylighting window that passes through the field frame. In particular, when a liquid crystal element is used, it is necessary to increase the transmittance of the liquid crystal element and simultaneously increase the contrast ratio of transmission and light shielding of the segment.

By the way, when the liquid crystal element is used for the display in the viewfinder, information such as numbers such as dates may be displayed in addition to the field frame. Generally, static drive or dynamic drive is used to display information on a liquid crystal element. The dynamic drive has a lower contrast ratio than the static drive, but the number of connections is only a fraction of the number of segments, depending on the duty. On the other hand, in static driving, the contrast ratio can be increased, but almost the same number of connections is required with respect to the number of segments. The increase in the number of connections is disadvantageous in terms of space and cost for mounting an electric circuit.

Although static drive is suitable for display information such as a field frame that requires a small amount of display information but requires high contrast, dynamic drive is suitable for display information that does not require much contrast but has a large amount of display information. It is suitable. From this point of view, US Pat. No. 5,170,204 uses a static drive type liquid crystal element for displaying a field frame and a dynamic drive type liquid crystal element for displaying photographing information outside the field frame. However, when the liquid crystal element is divided into a plurality of liquid crystal elements for static drive and dynamic drive, it is very disadvantageous in terms of space and cost.

It is an object of the present invention to provide a camera finder device in which a plurality of driving methods are selectively used according to display contents, and the display sections of both driving methods are combined on one liquid crystal element.

[0007]

When the invention of claim 1 is described in association with FIG. 1 showing an embodiment, a liquid crystal element 41 for displaying first photographing information and second photographing information in a finder. Applied to the viewfinder device of a camera having
The liquid crystal element 41 is provided with a first liquid crystal display unit 41b for displaying the shooting information of No. 1 in the first display drive system and a second liquid crystal display unit 41a for displaying the second shooting information in the second display drive system. By providing, the above-mentioned object is achieved. Claim 2
In the finder device according to the invention, the first liquid crystal display unit 41b displays the field frame by static drive, and the second liquid crystal display unit 41a displays the shooting information by dynamic drive. The invention of claim 3 is the same as claim 2
In the described device, the photographing information is information of characters and numbers. According to a fourth aspect of the present invention, in the apparatus according to the first or second aspect, the liquid crystal element 41 is provided with a third liquid crystal display unit 414 for displaying information imprinted on the film. According to a fifth aspect of the present invention, in the device according to the fourth aspect, the third liquid crystal display unit 414 displays information of characters and numbers by dynamic driving.

[0008]

The liquid crystal element 41 has the first and second liquid crystal display portions 4
1b and 41a are provided, the first liquid crystal display unit 41b displays the first photographic information by a first display drive system, for example, a static drive system, and the second liquid crystal display unit 41a displays the second photographic information. The display is performed by the second display driving method, for example, the dynamic driving method.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 2A and 2B are external views of the camera body 20 of this embodiment. On the upper surface of the camera body 20, a daylighting window 21 for guiding outside light to a finder optical path through a liquid crystal element 41 described later for displaying a field frame, and a data display for visually recognizing the date displayed on the liquid crystal element 41. A window 22 and a release button 23 are provided. A photographing lens 24 and an objective section 25 of a finder optical system are provided on the front surface of the camera body 20, and an eyepiece section 26 is provided on the back surface.
Is provided.

FIGS. 3 and 4 are views showing an embodiment of the structure of the finder device according to the present invention. The finder device of this embodiment includes a finder optical system 30 and a liquid crystal display device 40, and the finder optical system 30 includes the objective lens 3
1, an eyepiece lens 32, and a prism 33 provided between the objective lens 31 and the eyepiece lens 32 are fixed to a finder block 34. The viewfinder optical system 30 is provided with a liquid crystal display device 40 for displaying a field frame and various shooting information in the viewfinder.

The liquid crystal display device 40 is shown in FIGS. 2 (a) and 2 (b).
The liquid crystal element 41 provided to face the daylighting window 21 shown in FIG.
And a mirror 42 that reflects the light that has entered from the daylighting window 21 and transmitted through the liquid crystal element 41 to the prism 33, and the mirror 42.
And a condenser lens 43 for condensing the light reflected by the beam splitter section 33a of the prism 33. The liquid crystal element 41 is an adjustment member 44 on the finder block 34.
The mirror 42 and the condenser lens 43 are fixedly installed on the finder block 34. Reference numeral 45 is an adjustment screw for attaching the adjustment member 44 to the finder block 34.

As shown in FIG. 5A, the liquid crystal element 41 has a field frame display section 411 and a viewfinder information display section 4.
12, an AF target mark portion 413, and an imprinted data display portion 414 are provided. Field frame display section 4
Reference numeral 11 denotes a field-of-view frame which is a shooting range, and displays a panorama frame, a normal correction frame obtained by performing parallax correction on the normal frame, and the like. The field-of-view frame display unit 411 is configured as a negative-type element in which segmented portions of these frames are light-transmitting, and the liquid crystal display unit is driven by a static drive system.

The in-finder information display section 412 displays the shutter speed, aperture value, etc. below the field frame displayed in the finder. This finder information display section 412
Is configured as a negative type element in which a segment portion transmits light and displays letters and numbers, and is driven by a dynamic driving method. Since the in-viewfinder information display unit 412 is a negative type liquid crystal display unit, as shown in FIG. 3, a prism that shields the subject light by painting black on the lower side of the prism 33 on the front side of the camera body with a constant width. A light blocking member 33b is provided. As a result, bright characters are displayed on the black background.

The AF target mark display section 413 displays the focus detection area, is constructed as a negative type element, and is driven by a dynamic drive system. The imprint data display unit 414 confronts the above-described data display window 22 and displays the data imprinted on the film by an imprint mechanism (not shown). The imprinted data display unit 414 is configured as a positive type element in which a segment portion reflects light to display letters and numbers,
It is driven by a dynamic drive system. Therefore, a reflection plate (not shown) is attached to the back surface of the imprinted data display unit 414, and characters and numbers are displayed in black on a bright background.

FIG. 5B shows the connections among the field frame display section 411, the in-finder information display section 412, the AF target mark display section 413, and the imprinted data display section 414. Since the visual field frame display unit 411 is driven by the static drive system, a signal line is connected to each segment. On the other hand, in-finder information display section 4
12, the AF target mark display unit 413, and the imprint data display unit 414 are driven by a dynamic drive method, so that it is not necessary to connect each segment to each segment. When adopting the drive method, the number of connections can be significantly reduced compared to the static drive method.

FIG. 1 shows an example of a control system of this embodiment including a circuit for driving the above-mentioned liquid crystal display sections. Figure 1
In the figure, 51 is a control circuit including a CPU, 5
Reference numerals 2 and 53 are known photometry devices and distance measurement devices. The control circuit 51 calculates a shutter speed and an aperture value based on a signal from the photometric device 52 and a film sensitivity signal from a film sensitivity input unit (not shown). The control circuit 51 also includes the distance measuring device 5
The moving amount of the photographing lens 24 is calculated on the basis of the distance measurement signal from 3, and the AF lens is driven via an AF motor (not shown).

Reference numeral 54 is a liquid crystal drive circuit, which is a control circuit 51.
The information on the shutter speed and the aperture value is received from and the in-viewfinder information display unit 412 is driven through the dynamic drive circuit 55, and the display unit 412 displays the shutter speed and the aperture value. The liquid crystal drive circuit 54 also receives the imprint information from the control circuit 51, drives the imprint data display unit 414 via the dynamic drive circuit 55, and displays the imprint data display unit 414.
The imprinted data is displayed on 14. Further, the AF target mark display section 413 is driven via the dynamic drive circuit 55, and the AF target mark is displayed on the display section 413. The control circuit 51 determines the presence / absence of panoramic shooting and the presence / absence of parallax correction, drives the visual field frame display unit 411 via the static drive circuit 56, and causes the display unit 411 to display a desired visual field frame.

Various displays by such a finder device are performed as follows. The subject light enters the eyes of the photographer through the objective lens 31, the prism 33 and the eyepiece lens 32. On the other hand, the external light that has entered through the daylighting window 21 is transmitted only through the negative-type segment portion of the liquid crystal element 41. This external light is reflected by the mirror 42, passes through the condenser lens 43, is reflected again by the beam splitter portion 33a of the prism 33, and then enters the eye of the photographer through the eyepiece lens 32 together with the subject light. The negative type field frame display unit 411, the AF target mark display unit 413, and the in-finder information display unit 412 are driven by the static drive circuit 56 and the dynamic drive circuit 55, respectively, and the segment portion to which the voltage is applied is lighted. It is controlled to the transparent state. Therefore, the light transmitted through the light transmitting segment is observed by the photographer via the beam splitter section 33a of the prism 33. Prism 33
Since the prism light-shielding member 33b that shields the light from the subject is provided in the lower part of the front surface of the, the back surface of the in-viewfinder information display portion 412 displayed in the lower part of the viewfinder becomes dark and the display is very easy to see.

On the other hand, the positive type imprinted data display section 414 is driven by the dynamic drive circuit 55, the segment portion to which the voltage is applied is displayed in black, and the data imprinted on the film by the imprinting device (not shown). Is displayed.

In this embodiment, a positive type liquid crystal is used for the external display, but it is also possible to change the polarizing plate attached to the liquid crystal element 41 to a negative type. Although the bright frame finder is used in this embodiment, it can be applied to a real image type finder. In that case, a method is conceivable in which only the inside of the visual field frame is driven statically and the other parts are driven dynamically. Further, in the above description, four types of display units 411 to 414 are provided on one liquid crystal element 41, and the dynamic drive system and the static drive system are selectively used as necessary. The number and type of the display units are not particularly limited as long as the liquid crystal element includes at least one display unit and the second display unit driven by the static drive method.

[0022]

As described above, according to the present invention,
A first liquid crystal element and a second liquid crystal element which are driven by different methods for displaying various information in the finder.
Since the display section is provided, it is possible to provide a finder device excellent in cost and electrical mounting.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a control system of a camera to which a finder device according to the present invention is applied.

2A and 2B are external perspective views of a camera to which the finder device according to the present invention is applied.

FIG. 3 is a perspective view of an embodiment of a finder device according to the present invention.

4A and 4B show a configuration of an embodiment of a finder device according to the present invention, FIG. 4A being a plan sectional view and FIG. 4B being a side sectional view.

5A is a plan view of a liquid crystal element of an embodiment of a finder device according to the present invention, and FIG. 5B is a connection diagram thereof.

[Explanation of symbols]

 20 Camera Body 21 Lighting Window 22 Data Display Window 23 Release Button 24 Photographing Lens 31 Objective Lens 32 Eyepiece 33 Prism 33a Beam Splitter 33b Prism Shading Member 41 Liquid Crystal Element 411 Field Frame Display 412 AF Target Mark Display 413 Information in the Finder Display unit 414 Imprinted data display unit 42 Mirror 43 Condenser lens 51 Control circuit 52 Photometric device 53 Distance measuring device 54 Liquid crystal drive circuit 55 Dynamic drive circuit 56 Static drive circuit

Claims (5)

[Claims] 1. A finder device for a camera having a liquid crystal element for displaying first photographic information and second photographic information in a finder, wherein the first photographic information is displayed by a first display drive method. And a second liquid crystal display section for displaying the second photographing information by a second display driving method in the liquid crystal element. 2. The finder device for a camera according to claim 1, wherein the first liquid crystal display section displays a field frame by static drive, and the second liquid crystal display section displays shooting information by dynamic drive. Finder device for cameras. 3. The finder device for a camera according to claim 2, wherein the shooting information is information of characters and numbers. 4. The camera finder device according to claim 1, wherein the liquid crystal element is provided with a third liquid crystal display section for displaying information imprinted on a film. Finder device. 5. The finder device for a camera according to claim 4, wherein the third liquid crystal display section displays information of characters and numbers by dynamic driving.