JPH0694858A - Display device - Google Patents

Abstract

PURPOSE:To correct automatically the slippage of the display content of a pointer driven and rotated by a small size step motor. CONSTITUTION:At first, a pointer 12 is rotated responding to a display reset signal, and abutted to a stopper 13 provided at a specific position on a scale 11, and then, the pointer 12 is rotated in the reverse direction as a rotation amount integrating value from the position of the stopper 13. As a result, even though the display content is slipped, the display can be reset correctly depending on the rotation amount integrating value to indicate the accurate display content.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary pointer type display device for displaying various information.

[0002]

2. Description of the Related Art A timepiece using a step motor as a rotary drive source of a pointer is known. The step motor used in this type of timepiece is small in size, highly reliable, and mass-produced, so that it is inexpensive, and it can be considered to be used as a drive source for a display device other than the timepiece.

By the way, since the clock displays the time with the hands, it is not necessary to recognize where the hands are currently located. If the time is deviated from the standard time, the user can visually check and correct the time. . However, in a normal display device, it is necessary to set the pointer at the correct display position according to the information to be displayed, and therefore it is necessary to recognize the position of the pointer. However, the drive mechanism of the timepiece is not equipped with a detector for recognizing the position of the hands, so even if the needle content jumps due to some external force, and the displayed content shifts, it will automatically shift. It cannot be modified. However, if a position detection switch that detects the position of the pointer is provided, the driving load of the pointer increases and it becomes difficult to drive with a step motor for timepieces with weak output, and the device becomes large, Increase costs.

An object of the present invention is to automatically correct a deviation in display content of a pointer which is rotationally driven by a small step motor.

[0005]

The present invention will be described with reference to FIG. 2 showing a display device. In the invention of claim 1, various information is displayed by a pointer 12 rotating on a scale plate 11. The display means 2, a driving means for rotating the pointer 12, and a dial 12 are provided at predetermined positions on the scale plate 11.
Stopper 13 that limits the rotation of the
Integrating means for accumulating the rotation amount of the pointer 12 from the position 3; storage means for storing the integrated value of the integrating means; and rotating the pointer 12 by the driving means in response to the display reset signal to hit the stopper 13. After the contact, the control means for rotating in the opposite direction by the rotation amount integrated value stored in the storage means is provided, thereby achieving the above object. The invention of claim 2 is provided with an operating member 3 for resetting the display of the display means 2, and a display reset signal is issued when the operating member 3 is operated. According to the third aspect of the invention, the display reset signal is issued when the main switch of the camera is turned on. According to the invention of claim 4, the display reset signal is issued when the back cover of the camera is closed.
According to the fifth aspect of the invention, the display reset signal is issued when the battery compartment cover of the camera is closed.

[0006]

In response to the display reset signal, first, the pointer 12
Is rotated and brought into contact with a stopper 13 provided at a predetermined position on the scale plate 11. Next, the pointer 12 is rotated in the opposite direction by the rotation amount integrated value from the position of the stopper 13. As a result, even if the display position of the pointer 12 is deviated for some reason, the pointer can be correctly reset according to the rotation amount integrated value indicating the accurate display content.

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 in order to make the present invention easy to understand. It is not limited to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a camera equipped with a display device according to an embodiment, as viewed from the rear. In this embodiment, a frame number display device for displaying the number of captured frames will be described as an example. On the top surface of the camera body 1, a display device 2 for displaying the number of frames taken
And a display reset button 3 for resetting the display content of the display 2. 4 is a release button,
5 is a back cover of the camera.

FIG. 2 is an enlarged view of the display device 2. Display 2
Is a scale plate 11 in which “E” and the number of shooting frames of 1 to 36 are scaled, and a pointer 12 which is rotationally driven on the scale plate 11.
The pointer 12 rotates counterclockwise from the E position (hereinafter CCW
A stopper 13 is provided for restricting the rotation. In addition, 6 is a lens barrel.

FIG. 3 shows the structure of a camera having a display device according to an embodiment. Reference numeral 20 denotes a control circuit including peripheral components such as a microcomputer and a non-volatile memory (EEPROM) 20m. The control circuit 20 performs sequence control of the camera and various calculations, and executes a control program described later to perform display control. . 3a is a switch that is turned on when the display reset button 3 is pressed down, 4a is a switch that is turned on when the release button 4 is pressed halfway, 4b
Is a switch that is turned on when the release button 4 is fully pressed. Reference numeral 21 is a main switch of the camera, 22 is a switch that is turned on when the back lid 5 is opened, and 23 is a switch that is turned on when a lid of a battery chamber (not shown) is opened.
These switches are connected to the control circuit 20.

The control circuit 20 also includes a photometric device 24 for photometrically measuring the brightness of the subject, a focus detection device 25 for detecting the focus adjustment state of a photographing lens (not shown), and a film feeding motor 26.
A film feeding motor drive circuit 26 for driving M, a photographing lens drive circuit 28 for driving a lens motor 28M, a step motor drive circuit 29 of a step motor 29M for rotating the pointer 12, a shutter mechanism section 31, and an aperture mechanism section 32 are driven. An exposure control circuit 30 for controlling is connected.

FIG. 4 is a flow chart showing a main program executed by the microcomputer of the control circuit 20. The display process associated with the normal operation of the camera will be described with reference to this flowchart. When the main switch 21 is turned on, the microcomputer of the control circuit 20 starts executing this control program, and the main switch 2
When 1 is turned off, execution of the program ends. In step S1, it is determined whether or not the back cover 5 is closed by the switch 22, and when closed, the process proceeds to step S2, and it is determined whether or not a film is loaded by a film loading detection switch (not shown). If the film is loaded, the process proceeds to step S3, and if not, the process returns to step S1. As will be described later, when the film is loaded in the cartridge chamber and the back cover 5 of the camera is closed, the pointer 12 contacts the stopper 13 as shown in FIG.
Pointing to. In step S3, the film feed motor drive circuit 26 is controlled to control the film feed motor 26M.
The film is fed by and the first photographing frame is set at a predetermined photographing position. In a succeeding step S4, the step motor drive circuit 29 is controlled to move the pointer 1 by the step motor 29M.
Rotate 2 to the scale "1" and stop 1
The rotation amount θ of the pointer 12 from the position 3 is stored in the scale 20m.

In step S5, it is determined whether or not the release button 4 is half-pushed by the switch 4a. If the release button 4 is half-pushed, the process proceeds to step S6, in which the photometry device 24 performs photometry and the focus detection device 25 performs focus detection. .
In a succeeding step S7, the taking lens drive circuit 28 is controlled based on the focus detection result, and the lens motor 28M is driven to focus the taking lens. Further, in step S8, it is determined whether or not the release button 4 is fully pressed by the switch 4b, and if fully pressed, the process proceeds to step S9, the exposure control circuit 30 is controlled according to the exposure value calculated based on the photometric result, and the shutter mechanism is operated. Photographing is performed by the unit 31 and the diaphragm mechanism unit 32. Step S10 after shooting
Then, the film feeding motor drive circuit 26 is controlled to wind up one frame of film, and in the subsequent step S11, the step motor drive circuit 29 is controlled to move the pointer 12 in the clockwise direction for one frame (hereinafter referred to as CW). ) And rotate
The rotation amount of the pointer 12 this time is added to the rotation amount θ stored in the memory 20m, and the rotation amount θ of the addition result is stored in the memory 20m again.

In step S12, it is determined whether or not the photographing of all the photographing frames has been completed, and when the photographing is completed, step S12
13. If not completed, return to step S5.
In step S13, the film feeding motor drive circuit 26 is controlled to rewind the film, and then in step S1.
4, the step motor drive circuit 29 is controlled to rotate the pointer 12 in the CCW direction to set it at the position of the scale "E", that is, the position of the stopper 13, and the rotation amount θ = 0 is stored in the memory 20m.

As described above, the pointer 12 is rotationally driven according to the feeding amount each time the film is fed, and the stopper 1
The rotation amount θ from 3 is integrated and stored in the nonvolatile memory 20m. Therefore, the rotation amount θ of the pointer 12 does not disappear even when the camera is powered off.

Next, when the display reset signal described below is input, an interrupt occurs in the microcomputer. That is, when the display reset button 3 is operated to turn on the switch 3a and the input terminal 20a of the control circuit 20 changes from the high level to the low level, the main switch 21 of the camera is turned on and the input terminal 20b changes from the high level. When the level changes to low level, the back cover 5 is closed and the switch 22 turns off. When the input terminal 20c of the control circuit changes from low level to high level, the battery chamber cover closes and the switch 23 turns off. When the input terminal 20d changes from the low level to the high level, an interrupt occurs and the microcomputer executes the display reset routine shown in FIG.

First, in step S21, the timer is started, and in step S22, the step motor drive circuit 29 is controlled to rotate the pointer 12 in the CCW direction. In step S23, it is determined whether or not the timer has timed out. When the timer has timed out, the process proceeds to step S24 and the driving of the step motor 29M is stopped. At this time, the pointer 12 is in contact with the stopper 13 as shown in FIG. In addition, the pointer 12 is displayed at the maximum display position "3
6 ”to a position slightly longer than the time required to rotate the stopper 13 to the position. Next, in step S25, the rotation amount θ of the pointer 12 stored in the memory 20m is read, and in the subsequent step S26, the pointer 12 is rotated in the CW direction by the rotation amount θ.

In this way, the display reset signal causes the microcomputer to interrupt, the pointer is brought into contact with the stopper provided at a predetermined position on the scale plate in the interrupt routine, and then the rotation stored in the memory is performed. Since it is rotated in the opposite direction by the amount θ, even if the display content is deviated for some reason, the display content is automatically corrected.

In the above-mentioned embodiment, the photographing frame number display device has been described as an example, but the display device of the present invention has a strobe mode, a self-timer mode, an exposure correction value, an aperture value, a shutter speed, a photographing distance and the like. The present invention can be applied not only to a display device that displays various shooting information of a camera, but also to a display device other than the camera.

In the configuration of the above embodiment, the indicator 2 serves as display means, the step motor drive circuit 29 and the step motor 29 serve as drive means, the stopper 13 serves as a stopper, and the control circuit 20 serves as integrating means and control means. The memory 20m constitutes a storage means.

[0021]

As described above, according to the present invention, the pointer is rotated in response to the display reset signal and brought into contact with the stopper provided at a predetermined position on the scale plate, and then the rotation amount is integrated. Since the pointer is rotated in the opposite direction by the value, even if the display content shifts due to some reason, the display content is automatically corrected.

[Brief description of drawings]

FIG. 1 is a perspective view of a camera provided with a display device of the present invention as seen from the rear.

FIG. 2 is an enlarged view of a display device.

FIG. 3 is a block diagram showing a configuration of a camera including a display device according to an embodiment.

FIG. 4 is a flowchart showing a main program of a microcomputer.

FIG. 5 is a view showing a state in which a pointer is brought into contact with a stopper.

FIG. 6 is a flowchart showing a display reset routine.

[Explanation of symbols]

 1 Camera body 2 Display 3 Display reset button 3a, 4a, 4b, 22, 23 switch 4 Release button 5 Back cover 6 Lens barrel 11 Scale plate 12 Pointer 13 Stopper 20 Control circuit 20a-20d Input terminal 20m Memory 21 Main switch 24 Photometry device 25 Focus detection device 26 Film feeding motor driving device 26M Film feeding motor 28 Photographing lens driving circuit 28M Lens motor 29 Step motor driving circuit 29M Step motor 30 Exposure control circuit 31 Shutter mechanism part 32 Aperture mechanism part

Claims (5)

[Claims] 1. A display means for displaying various kinds of information by means of a pointer that rotates on a scale plate, a drive means for driving the pointer to rotate, and a rotation means for restricting the rotation of the pointer, which is provided at a predetermined position on the scale plate. Stopper, an integrating means for integrating the rotation amount of the pointer from the stopper position, a storage means for storing the integrated value of the integrating means, and a rotating means for rotating the pointer by the driving means in response to a display reset signal. A display device, comprising: a control unit that rotates in the opposite direction by the rotation amount integrated value stored in the storage unit, after being brought into contact with the stopper. 2. The display device according to claim 1, further comprising an operation member for resetting a display of the display means, wherein the display reset signal is generated when the operation member is operated. Display device. 3. The display device according to claim 1, wherein the display reset signal is generated when a main switch of the camera is turned on. 4. The display device according to claim 1, wherein the display reset signal is issued when the back cover of the camera is closed. 5. The display device according to claim 1, wherein the display reset signal is generated when the battery chamber cover of the camera is closed.