JP3045853B2 - Display control device in viewfinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder display control device for controlling a display in a finder of a camera.

[0002]

2. Description of the Related Art Conventionally, cameras configured to display various information in a finder using a light emitting diode or the like so that a photographer can recognize a shutter speed or the like when operating the camera have been widely used. I have. When such a display in the finder is performed during the shutter release, the light of the light emitting diode reaches the film surface and so-called fogging may occur on the film, so the light emitting diode is turned off simultaneously with the start of the shutter release, and the film is turned off. At the time of completion of the winding of the light emitting diode.

In the above control, if the light emitting diode is turned off for the entire period during the shutter release operation, there is a problem that the display disappears for a long time, and it is difficult for the photographer to see the display in the viewfinder. For example, in the continuous shooting mode in which a plurality of photographs are continuously taken, the display remains off during the continuous shooting, so that the shutter speed or the like cannot be confirmed in the viewfinder.

[0004] Therefore, if control is performed so as to interrupt the display only during the period when the shutter is substantially opened, the time during which the display disappears is shortened.

[0005]

However, if the display is interrupted only during the period in which the shutter is substantially opened, the display in the viewfinder will blink, for example, when taking a picture in the continuous shooting mode. There is a problem that the visibility of the display in the viewfinder is not always improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its main object to prevent the occurrence of film fogging due to the display in the viewfinder and to make the display in the viewfinder easier to see. It is an object of the present invention to provide a display control device in a viewfinder.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a display control device in a viewfinder for controlling the display of information accompanied by illumination in the viewfinder of a camera, wherein the display is selectively interrupted. Means for detecting a set shutter speed, operation for interrupting display of information only during a period when the shutter is substantially opened according to the set shutter speed, and opening and closing of the shutter during a release operation Means for selecting an operation for continuing to display information even when the display control device in the finder is provided.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

FIG. 1 shows a configuration of a control circuit in a camera 1 to which the present invention is applied. The control circuit includes a microprocessor (CPU) 3 for controlling the entire camera, a microprocessor (DPU) 4 for controlling input and output of photometric data and the like, and a microprocessor (IPU) 5 for controlling input and output of display and the like. And a microprocessor (lens CPU) 6 for controlling aperture information and focal length information of the photographing lens, and controlling zooming and the like. Of these, only the lens CPU 3 is provided on the taking lens 2 side,
Others are provided in the camera body 1.

The CPU 3 performs various sequence controls, AF operations, exposure calculations, and the like. For this reason C
The PU 3 is connected with an EE circuit 11 that generates a pulse synchronized with the aperture-down operation, a switch circuit 12 for inputting signals from various switches such as a photometric switch and a release switch, and motor drive circuits 13 and 14. ing. The motor drive circuit 13 includes a mechanical charge motor 15,
This is a circuit for driving a wind motor 16 for winding a film, and the motor drive circuit 14 is a circuit for driving an AF motor 17. The CPU 3 stores information such as the number of films and various correction values.
^{2 The} PROM 18, a pair of magnets 19 and 20 for electrically holding the shutter, and a magnet 21 for releasing the locked state of the mirror are connected.

The DPU 4 has a CCD 2 as a distance measuring sensor.
2 and a photometric I that outputs a voltage signal according to the brightness of the subject
C23 is connected to the DPU 4, and the DPU 4 performs a photometric operation and functions as an interface of the CCD 22. Also, the DPU 4 and the CPU 3 have LEDs (described later) for displaying various information in the finder.
The display device 24 is connected.

The IPU 5 has an LCD display device 25 for displaying various information outside the camera body 1, a flash circuit 26, and a switch for switching between an exposure mode, a film feeding mode, a film sensitivity mode, and the like. The circuit 27 is connected.

The lens CPU 6 is a CPU 3 on the camera body side.
The CPU 3 transmits and receives information on various lenses to and from the CPU 3 and performs various calculations based on the information. Further, a motor drive circuit 31 and a switch circuit 32 are connected to the lens CPU 6. The motor drive circuit 31 is a circuit for electrically driving the power zoom motor 33, that is, the photographing lens, and the switch circuit 32 is a circuit for controlling mode switching between power zoom and manual zoom. is there.

FIG. 2 shows a light emitting diode (LED) 41 constituting a main part of the display device 24 in the finder, and a switching transistor 4 for controlling turning on and off of the light emitting diode (LED).
2, 43 are shown. The base of the switching transistor 42 is connected to the CPU 3. Further, the base of the switching transistor 43 is connected to the DPU 4. These transistors 42 and 43 are turned on when a signal is input to their bases, and when both transistors 42 and 43 are turned on, the light emitting diode 41 emits light and the display device 2
4 can be visually recognized in the viewfinder.

A normal ON signal is output from the CPU 3 to the transistor 42. Also, DPU4 is IPU
An ON signal is output to the transistor 43 based on a signal output from the PU 5, that is, based on states of various switches. Therefore, these transistors 42 and 43 are turned on before the shutter release operation,
The display device 24 is lit at the start of the release operation.

When the release operation is started, the DPU 4 continues to output an ON signal.
As shown in the flowchart, the off signal is output while the shutter is open according to the shutter speed. As a result, the display device 24 selectively interrupts the display while the shutter is open according to the shutter speed.

Next, with reference to FIGS. 3 to 7, a procedure for controlling the display in the finder accompanying the release operation will be described. Here, FIG. 3 is a main flow up to a shutter release operation, FIG. 4 is a flow showing a shutter release operation, FIGS. 5 and 6 are flows showing a film wind process, and FIGS.
7 is a timing chart showing a shutter release sequence.

The main flow shown in FIG. 3 is started by turning on a photometric switch or the like, which is a push button switch that also functions as a release switch. First, the ports, AE, and AF are initialized in steps 1 to 3, and the 100 mS timer and the 4 mS timer are started in steps 4 and 5. Then, in step 6, the states of various switches are read, and the process proceeds to step 7 where AF processing is performed. Next, in step 8, it is determined whether or not the time of the 100 mS timer has expired. If the time has expired, photometric data is input from the DPU 4 to the CPU 3 in step 9, and photometric calculation processing is performed based on the data (step 9). After step 10), the result is displayed on the display device 24 and output to the IPU 5 for display on the display device 25 (step 1).
1) After resetting the 100 ms timer (step 1)
2) Return to step 6 and repeat the above routine.

On the other hand, if the 100 mS timer has not expired in step 8, the process proceeds to step 13, where it is determined whether or not the 4 mS timer has expired.
If not, the process returns to step 6, and if the time is up, the process proceeds to step 14. In this step 14, it is determined whether or not the release switch has been turned on. If the switch has not been turned on, the flow proceeds to step 15, after resetting the 4 ms timer, returns to step 6, and repeats the above routine. If the release switch is on, the shutter release operation flow shown in FIG. 4 is executed.

In the shutter release operation flow, when a release switch is turned on (portion A in FIG. 7), a 60 ms timer is started in step 101. This timer is for securing the time (part B in FIG. 7) necessary for the electrical and mechanical operation for performing the narrowing-down control. Next, in step 102, the shutter magnets (the first curtain Mg19 and the second curtain Mg20) are turned on (C in FIG. 7).
), The shutter is held closed, and at the same time, the release magnet (release Mg21) is turned on (part D in FIG. 7) to release the locked state of the mirror. Then, the process proceeds to step 103, where the mirror-up operation is started (portion E in FIG. 7), and the narrowing-down operation is also started. In this narrowing-down operation, the EE circuit 11 is started to start counting EE pulses (portion F in FIG. 7) (step 10).
4) This EE pulse is a pulse output in conjunction with the narrowing-down operation. When the number of EE pulses reaches a predetermined value,
The E magnet (EEMg) is energized for 5 mS (step 105, part G in FIG. 7). As a result, the slide plate, that is, the diaphragm stops at a predetermined position, and the diaphragm value is determined.

Then, the process proceeds to a step 106, wherein a step 10
It waits until 60 mS elapses from the start of the first timer, and when 60 mS elapses, the routine proceeds to step 107, where the shutter speed determined in the flow of FIG. 3 is faster than a first predetermined time, for example, the synchronizing speed of the camera. If it is fast, the process directly proceeds to step 109, and if it is not fast, the display in the finder, that is, the display on the display device 24 is interrupted in step 108 (transistor 42
Is turned off), and the process proceeds to step 109. In this step 109, the shutter magnet (first curtain Mg19) is turned off (1C in FIG. 7) and the front curtain is driven (H in FIG. 7).

Then, the process proceeds to a step 110, wherein it is determined whether or not the shutter speed is faster than a second predetermined time.
If it is faster (for example, 1/30 or more), the process proceeds to step 111, and waits until the set shutter release time elapses.
g20) is turned off (portion 2C in FIG. 7), and the rear curtain is driven (portion I in FIG. 7). Then, after waiting until the rear curtain travel is completed in step 113, step 114 is executed.
The display of the display device 24 is restarted, and the flow shifts to the flow of the film wind processing (FIGS. 5 and 6).

On the other hand, if the shutter speed is slower than the second predetermined time in step 110 (for example, 1/15 or less), the camera waits until the shutter opening time set in steps 115 and 116 elapses, and It is monitored whether or not the main switch is turned off. If the main switch is turned off, the process proceeds to step 112 even before the shutter opening time has elapsed, and the subsequent steps are executed.

Next, the flow of the film winding process shown in FIG. 5 will be described. First, in step 121, the charge motor is started, and the mirror down (part J in FIG. 7) and the shutter charge (part K in FIG. 7) are started. In step 122, the wind motor is started to wind the film. Start. Next, in step 123, a 20 mS timer is started, and in step 124, the charge motor and the wind motor are pulse-driven (duty ratio control) (portions L and M in FIG. 7). By this pulse driving, the rotations of the charge motor and the wind motor gradually increase. Then, the process proceeds to step 125, and waits until 20 ms elapses from the start of the timer in step 123, and then ends the pulse driving.
At 26, the charge motor and the wind motor are driven by DC (N and O portions in FIG. 7).

In step 127, a 100 mS timer for recognizing the end of the film when winding the film is started. Next, the process proceeds to step 128 in FIG. 6 to determine whether or not the wind pulse has changed. While the change is detected, the 100 mS timer is reset in step 129 and whether or not the winding is completed in step 130. Is determined. When the winding of the film is completed in step 130, the flow advances to step 131 to stop the wind motor. Then, it waits until a completion signal (part P in FIG. 7) from the charge completion switch is detected in step 132, and when it is detected, the charge motor is stopped and the power is turned off in step 133.

On the other hand, if no change in the wind pulse is detected in step 128, the end of the film is determined in steps 134 to 139. That is, in step 134, the completion signal from the charge completion switch (FIG. 7)
If (P) is detected, the charge motor is stopped in step 135, and if no completion signal is detected, the process immediately proceeds to step 136. This step 1
At 36, it is determined whether 100 ms has elapsed since the execution of step 127 or 131, and if 100 ms has elapsed, the process proceeds to step 137, where the wind motor is stopped. Then, when it is confirmed in step 138 that the charging has been completed, the charging motor is stopped in step 139, and the process proceeds to a film termination process (not shown).

As described above, in this embodiment, when the shutter speed is somewhat slow, the shutter magnet (front curtain M
g19) is turned off, and the display in the viewfinder is interrupted only after the front curtain has traveled and the travel of the rear curtain has been completed, that is, only during the period when the shutter is substantially opened (part Q in FIG. 7). It has become. When the shutter speed is high, the display in the viewfinder is always performed regardless of the opening and closing of the shutter. Therefore, the display interruption period of the display device 24 when the shutter speed is low is shorter than before, and the display in the viewfinder is easy to see. When the shutter speed is high, the display on the display device 24 is always performed even during the shutter release operation in the continuous shooting mode, so that the visibility such as the shutter speed is improved.

[0028]

As is apparent from the above description, according to the display control apparatus in a finder according to the present invention, when the set shutter speed is lower than a predetermined speed, only when the shutter is substantially open. When the display of information is interrupted and the shutter speed is equal to or higher than the predetermined speed, the information is continuously displayed even if the shutter is opened and closed, so that the display in the viewfinder can be easily viewed without causing fogging on the film.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of a camera having a display control device in a finder to which the present invention is applied.

FIG. 2 is a diagram illustrating a switch circuit for controlling a display device.

FIG. 3 is a main flowchart up to a shutter release operation.

FIG. 4 is a flowchart showing a shutter release operation.

FIG. 5 is a flowchart showing a first half of a film wind process.

FIG. 6 is a flowchart showing the latter half of the film wind processing.

FIG. 7 is a timing chart showing a shutter release sequence.

[Explanation of symbols]

1 camera 2 taking lens 3 CPU 4 DPU 5 IPU 6 lens CPU 11 EE circuit 12 the switching circuit 13, 14 motor driving circuit 15 mechanical charge motor 16 wind motor 17 AF motor 18 E ² PROM 19, 20, 21 magnet 22 CCD 23 photometry IC 24 display device 25 display device 26 flash circuit 27 switch circuit 31 motor drive circuit 32 switch circuit 33 power zoom motor 41 light emitting diode 42, 43 switching transistor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 17/18-17/20

Claims (3)

(57) [Claims] 1. A display control device in a viewfinder for controlling display of information accompanied by illumination in a viewfinder of a camera, comprising: means for selectively interrupting display; means for detecting a set shutter speed; Means for selecting an operation of interrupting display of information only during a period when the shutter is substantially opened according to the set shutter speed during the release operation, and an operation of continuously displaying information even when the shutter is opened and closed; A display control device in a finder, comprising: 2. When the set shutter speed is lower than a predetermined speed, the display of information is interrupted only during a period when the shutter is substantially opened, and when the shutter speed is equal to or higher than the predetermined speed, 2. The display control device according to claim 1, wherein the information is continuously displayed even when the shutter is opened and closed. 3. The display control device according to claim 2, wherein the predetermined speed is a synchro tuning speed.