JPS6298334A - Display device for state of film in camera - Google Patents

Abstract

PURPOSE:To prevent external light from leaking into a camera by detecting electrically and displaying the winding and rewinding states of a film. CONSTITUTION:When a film winding switch 20 is turned on, a winding drive part 30 operates to wind the film by specific length. Simultaneously, a pulse generator 40 generates a pulse signal A, which is inputted to a display control part 50. At this time, it is decided from the phase of the signal A whether the film is wound or rewound. The control part 50 when detecting the winding state outputs a display switching signal B to a display drive part 60, which operates to make a winding display 80. When this winding operation is completed, a calendar and timer circuit 70 sends information on a photography date, time, etc., to the drive part 60, which makes a calendar to time display 80. This operation is carried out every time the film is wound. When a rewinding switch 90 is turned off, a rewinding drive part 100 operates and the display control part 50 detects the phase of the signal A and the rewinding or winding state, so that the display device 80 display the rewinding state through the operation of the drive part 60.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a film status display device that displays whether the film in a camera is in a winding or rewinding state.

[Prior art and its problems] Conventionally, various methods have been provided for displaying the winding and rewinding status of the film loaded inside the camera. For example, as shown in FIG. Some cameras display these statuses by mechanically operating an indicator in a confirmation window C6 provided at the top of the camera body or an indicator in a confirmation window (not shown) provided at the top of the camera body.

However, when the status is displayed through the confirmation window C9 provided on the back cover C4, there is a risk that external light may leak into the camera through the confirmation window cS.

Furthermore, since the indicator in the confirmation window C8 is driven by a rotating roller or the like that is driven in contact with the film, there is a risk that the film may be damaged depending on the accuracy of the rotating roller or the like.

[Object of the Invention] The present invention has been proposed in view of the above points, and its purpose is to electrically display the status of film winding, rewinding, etc., and to use a mechanical indicator. It is an object of the present invention to provide a film status display device for a camera that prevents light leakage from the camera back cover and eliminates the risk of damaging the film.

[Structure of the Invention] In order to achieve the above object, the present invention electrically detects whether the film is being wound up or rewound by a film movement detection means, and based on this detection signal, the back of the camera is detected. By driving an electric indicator provided on the lid or the like, status indicators such as the winding or rewinding status of the film can be confirmed from the outside.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram for status display in the present invention. First, the film detection switch 10 detects that the end of the film pulled out from the film cartridge loaded inside the camera body is one winding bobbin C, ( This is to detect the presence of this film when it is pulled out close to the film (see Figure 3), and for example, a detection switch 11 etc. is planned to be placed at the position shown in Figure 2. However, as shown in FIG. 2 or 3, the window C inside the camera body C
2 and by closing the back cover C3.
A detection switch 12 that is turned on may also be included.

Referring again to FIG. 1, the one-winding switch 20 is, for example, a switch that is linked to the shutter, and is turned on each time the shutter is pressed once.

The winding drive section 30 is for driving a winding motor (not shown) to rotate the sprocket 31 in FIG. 2 when both the film detection switch 10 and the winding switch 20 are turned on.

Next, the pulse generator 40 generates a pulse signal in conjunction with the winding drive unit 30 to detect that the film is moving during winding (or rewinding). It is constructed as shown in FIG. That is, this pulse generator 40 includes a transmission gear 41 attached coaxially with the sprocket 31, and a transmission gear 41 attached coaxially with the sprocket 31.
A transmission gear 42 meshing with the transmission gear 42, a slit circle @43 coaxially attached to the transmission gear 42, and the slit disk 4
A photocoupler 45 detects a pulsed optical signal transmitted through a plurality of slits 44 formed in the photocoupler 3 and converts it into an electrical pulse signal.

It should be noted that the film movement detecting means 1 is constituted by this pulse generator 40, the upstream winding drive unit 30, and the rewinding drive unit lOO, which will be described later.

The output signal of this pulse generator 40 is transmitted to the display control section 5 of the next stage.
Added to 0. This display control section 50 determines the state of the film based on the pulse signal from the pulse generator 40, and generates a display switching signal to switch the display content of the display 80 via the next-stage display drive section 60. It is made up of, for example, a circuit for detecting the phase of the pulse signal from the pulse generator 40.

A well-known calendar/clock circuit 70 for imprinting the photographing date, time, etc. on the negative is connected to the display drive section 60, and the next stage display 80 is connected to the display drive section 60 based on the output signals of these circuits.
In addition, a status display circuit is provided for displaying the winding/rewinding status of the film in response to a display switching signal from the display control section 50.

The display 80 is composed of an electrical display element such as a liquid crystal or a 7-segment LED, and is mounted at a position that is easily visible to the photographer, such as the center of the camera back cover C1, as shown in FIG. It will be done.

On the other hand, the rewind switch 90 is turned on when a predetermined number of films have been taken, and is a manually operated switch.
Alternatively, the switch may be turned on by optically or electrically detecting that most of the film has been wound onto the winding bobbin C.

The output signal of the rewind switch 90 is transmitted to the rewind drive section 10.
In this rewind drive unit 100, the film cartridge is driven by a rewind motor, and all the film on the winding bobbin C1 side is wound into the film cartridge. At this time, since the sprocket 31 (see FIG. 2) rotates following the film being wound up, the pulse generator 40 operates in conjunction with the rewind drive section 100.

Note that when winding the film for shooting, the number of output pulses from the pulse generator 40 is counted by the counter 110.
It is possible to stop the winding motor of the winding drive unit 30 when one frame of film has been wound, or to perform a similar operation by detecting the number of revolutions of the winding motor. .

Further, among the above components, all except the display 80 are built into the camera body C side, and only the display 80 is installed on the back cover C1.
The electrical connection between the 1 display 80 and the display drive unit 60 on the camera body C side is shown in FIG. This can be done using the connectors 81.61 as shown in FIG.

Next, this operation will be explained. After loading the film into a predetermined position in the camera body C, closing the back cover C1 turns the film detection switch 10 ON, and then when the shutter is released for aerial shooting, the winding switch 20 turns ON. As a result, the winding drive unit 30 operates to rotate the sprocket 31 and wind the film by a predetermined length.

During this time, the slit disk 43 rotates and the pulse generator 40
A predetermined number of pulse signals are output from the display controller 50, and these pulse signals are input to the display control section 50. here.

If the pulse generator 40 is constituted by, for example, a rotary encoder, the rotational direction of the slit disk 43, that is, whether the film is wound up or rewound, can be determined based on the phase of the pulse signal. In this case, since the film is wound up, the display control unit 50 detects that the film is in the wound state,
Based on this, a display switching signal is output. This display switching signal is applied to the display drive unit 60, and the display drive unit 60
For example, as shown in FIG.
is displayed on the display 80 in the form of a directional chain line that blinks in this order.

When the film is advanced by one frame and ready for photography, the slit disk 43 has already stopped and the pulse generator 4
0 and there is no output signal from the display control unit 50, so instead of the previous winding display, information such as the photographing date and time is sent from the calendar/clock circuit 70 to the display drive unit 60, and as shown in FIG. A calendar or time display as shown in (b) and (c) is displayed. From then on, the above-mentioned operation is repeated every time the film is wound up after the shutter is released, and every time the film winding is finished, as shown in Fig. 5 (a) and 5 (a).
(b) or (c) is displayed.

When all the films have been shot, the rewind switch 90, which can be one-handed or automatic, is turned on to activate the rewind drive section 100 and rewind the film into the film cartridge.

At this time, since the slit disk 43 rotates in reverse in conjunction with the film and sprocket 31, the phase of the pulse signal from the pulse generator 40 is also reversed, and the display control unit 50 detects that the film is in the rewinding state. do. Therefore,
The display driving section 60 receives the display switching signal based on the film rewinding state.

As shown in FIG. 5(d), the display b1. b2. b) is used to display a directional chain-line rewind display on the display 80 that blinks in this order. Note that the rewinding motor may be stopped using a well-known optical or electrical sensor.

In this manner, this embodiment is extremely convenient for the photographer because the 1 display 80 provides an electrical indication indicating the direction of film movement when the film is wound up or rewound.

, Effects of the Invention] As described above, the present invention electrically detects and displays the state of film winding, rewinding, etc., so when the display is disposed on the back cover of a camera, for example. However, by adopting a structure in which a one-chip display is embedded in the camera back, leakage of outside light into the camera is completely eliminated compared to conventional confirmation windows with mechanically driven indicators. can be prevented.

That is, in the conventional system, the indicator is indirectly connected to the film via a rotating roller or the like, so that external light from the confirmation window easily reaches the film, but in the present invention, the indicator and the film are connected together. This type of inconvenience does not arise because it can be completely mechanically isolated.

At the same time, there are various advantages, such as eliminating the need for conventional rotating rollers and the like, and eliminating the risk of damaging the film.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a block diagram for displaying the status, Fig. 2 is a perspective view of the pulse generator, etc., Fig. 3 is a perspective view of the camera, and Fig. 4 is the rear view. A perspective view of the lid, FIGS. 5(a) to 5(d) are explanatory diagrams of the display contents of the display, and FIG. 6 is a perspective view of the back lid showing a conventional example.

Claims (2)

[Claims] (1) a film movement detecting means for detecting whether the film inside the camera body is in a winding state or a rewinding state; a display control section generating a display switching signal based on an output signal of the film movement detecting means; a display drive unit that switches between a calendar/time display and a film winding or rewinding status display based on a display switching signal; and a display drive unit that is connected to the display drive unit and attached to the camera so that the displayed content can be checked from the outside. 1. A film status display device for a camera, characterized in that it is equipped with an electrical display device. (2) As an indication of the state of film winding or rewinding, a display element of a display device is made to blink sequentially in a certain direction corresponding to the winding direction or rewinding direction of the film. film status display device for cameras.