JP3857836B2 - Zoom camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera having a zoom-type imaging lens, and more particularly to a zoom-type camera that enables both shooting on a photosensitive film and shooting using an imaging device such as a CCD.
[0002]
[Prior art]
In recent years, there has been proposed a still camera that enables both photographing on a photosensitive film and electronic photographing using an image sensor such as a CCD. In this type of camera, a subject image formed by a photographing lens is exposed to a photosensitive film, or is coupled to an image sensor to perform photographing using an imaging signal. In this case, in a camera configured with a zoom lens as a taking lens, in the case of a single-lens reflex camera, the zoom state of the taking lens can be confirmed with a viewfinder, but with a camera equipped with an optical viewfinder independent of the taking lens, The optical viewfinder needs to be zoomed in conjunction with the zoom operation of the photographic lens. Therefore, this type of camera requires a zoom mechanism for zooming the photographic lens and a zoom mechanism for zooming the optical viewfinder, and both zoom mechanisms must be driven for zoom operation. It becomes.
[0003]
[Problems to be solved by the invention]
When performing such zoom operation, it is necessary to drive both zoom mechanisms of the taking lens and the optical viewfinder, and in particular, the zoom mechanism of the taking lens needs to drive a large-diameter lens, which is relatively large. Electric power is required, and the power consumption cannot be ignored. In addition, the shooting angle of view of the subject is checked while variously changing the focal length at the time of shooting, but the current consumption in the zoom mechanism of the shooting lens and optical viewfinder at this time cannot be ignored, and the battery capacity This causes premature wear. There has also been proposed a camera in which the optical finder is configured with a fixed focus optical system and only the photographing lens is configured with a zoom optical system. In this camera, at least the zoom mechanism in the optical finder is driven. However, even in this type of camera, it is difficult to avoid an increase in battery capacity due to the zoom operation of the photographing lens during photographing.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom camera that limits the zoom operation in a photographing lens or an optical viewfinder and reduces power consumption associated with the zoom operation.
[0005]
[Means for Solving the Problems]
The present invention, focus is set by the focal length setting means and the focal length setting means for setting a photographing lens including a zoom mechanism for capturing a subject, the focal length by controlling the pre-Symbol zoom mechanism In a zoom camera comprising a monitor device for displaying the subject on a monitor at a zoom magnification corresponding to the distance, the photographing lens is set to a focal length set by the focal length setting means by the zoom mechanism during a photographing operation. Means, a distance measuring means for measuring the subject, a means for repeatedly detecting the distance measurement data by the distance measurement means, and the distance measurement data has reached a predetermined number of times, and the distance measurement data Means for immediately setting the photographic lens to a focal length set by the focal length setting means by the zoom mechanism when is within a predetermined range Characterized in that it comprises a.
[0006]
Here, in the present invention, an imaging device disposed in one of the optical systems of the photographing lens or an optical finder provided independently of the imaging lens, and an imaging signal captured by the imaging device. A signal processing circuit that performs signal processing and displays the image on the monitor device as an image, and the signal processing circuit includes an electronic zoom circuit that performs an electronic zoom process on an image signal captured by the image sensor and displays the image on the monitor device. provided, the electronic zoom circuit arbitrariness preferred that a configuration of controlling the zoom magnification corresponding to the focus distance is set to monitor images at the focal length setting means.
[0007]
According to the present invention, immediately before shooting, the subject image is displayed on the monitor at a zoom magnification corresponding to the focal length set by the focal length setting means, so that the subject can be shot without driving the zoom mechanism of the taking lens. The angle of view can be confirmed. At the time of shooting, the shooting lens is set to the focal length set by the focal length setting means, and shooting at the set focal length can be realized. Further, distance measurement is performed a plurality of times during photographing, and when the distance measurement data is within a predetermined range, the photographing lens is immediately set to the focal length set by the focal length setting means. Therefore, the zoom mechanism of the photographic lens and the optical finder is not operated until immediately before shooting, and the power consumption of the zoom mechanism during that time can be reduced, and the battery consumption can be suppressed. On the other hand, the timing at which the photographic lens is set to a predetermined focal length is advanced, and a release operation with high responsiveness can be realized.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the zoom camera of the present invention, and FIG. 2 is a schematic perspective view of the main part thereof. The photographing lens 1 includes an internal focal length detection unit 2 and is configured as an optical zoom lens incorporating a zoom mechanism 3 having a motor 100 as a driving source. The focal length of the photographing lens 1 is driven by the zoom driving circuit 4. Variable. The photographing lens 1 is provided with a focus driving circuit 5 for focusing on a subject, a shutter driving circuit 6 for driving a shutter at the time of photographing, and a diaphragm driving circuit 7 for operating a diaphragm at the time of photographing. It is controlled by a microcomputer (hereinafter abbreviated as a microcomputer) 10. The taking lens 1 forms a subject image on the photosensitive film 8 and forms a latent image on the photosensitive film 8. The photosensitive film 8 is rolled up and rewound by a film driving circuit 9 controlled by the microcomputer 10. On the other hand, the optical finder 11 is configured as a zoom finder that follows the zoom operation of the photographic lens 1 and has a field angle of view corresponding to the focal length of the photographic lens 1, and the zoom mechanism 12 includes the photographic lens 1. The zoom mechanism 3 is operated in conjunction with the zoom mechanism 3. In addition, a half mirror 13 is built in the optical finder 11, and a CCD image sensor 14 as an image sensor is disposed at a position facing the half mirror 13, and a subject to be observed with the optical finder 11. A part of the finder image light is reflected by the half mirror 13, and this reflected light is photoelectrically converted by the CCD image pickup device 14 and output as an image pickup signal.
[0009]
The zoom mechanism 3 of the photographing lens 1 and the zoom mechanism 12 of the optical viewfinder 11 will be briefly described with reference to FIG. 2. The zoom ring 101 provided on the photographing lens 1 is replaced with a drive gear 102 of the motor 100. , The lens 103 is moved in the optical axis direction of the photographic lens 1 by an unillustrated helicoid mechanism provided inside, and the focal length of the photographic lens 1 is changed. Further, a gear train 104 meshed with the zoom ring 101 is meshed with a driven gear 106 integrated with a ball screw 105 provided along the optical axis direction of the optical finder 11. When the ball screw 105 follows the zoom ring 101 and rotates, the lens 108 integrated with the boss 107 screwed to the ball screw 105 is moved in the optical axis direction of the optical viewfinder 11. The focal length is configured to change following the photographing lens 1. Although not shown in FIG. 2, the zoom mechanism 3 includes an encoder for detecting the amount of rotation of the zoom ring 101, a potentiometer for detecting the movement position of the lens 103 in the optical axis direction, and the like. The focal length detection unit 2 (see FIG. 1) for detecting the focal length of the photographic lens 1 driven and controlled by the zoom mechanism 3 is provided, and the focal length detected by the focal length detection unit 2 is determined as the focal length. It is configured to input to the microcomputer 10.
[0010]
The CCD element 14 is driven by a CCD drive unit 15 controlled by the microcomputer 10, and an image signal picked up by the CCD element 14 is input to a signal processing unit 16. The signal processing unit 16 suppresses noise included in the imaging signal output from the CCD element 14 by correlated double sampling in the CDS circuit 17 and converts the imaging signal into a digital signal by the A / D conversion circuit 18. Obtain imaging data. Further, the obtained imaging data is temporarily stored in the first field memory 19, and then the imaging data is sequentially read out from the first field memory 19, and the signal processing circuit 20 performs various processes such as shading correction, gamma correction, and compression. To do. The imaged data subjected to this signal processing is stored in the second field memory 21, and then sequentially read out, converted into an analog signal by the D / A conversion circuit 22, and output as a video signal. The signal-processed imaging data is stored in the flash memory 23 by the flash memory controller 24 along with the release operation. Here, the signal processing circuit 20 includes an electronic zoom circuit 25, and the digital signal stored in the first field memory 19 is electronic zoom processed and recorded in the second field memory 21 as will be described later. It is possible to do. The video signal output from the signal processing unit 16 is sent to an LCD (liquid crystal) driving circuit 26 and displayed as a monitor video on the LCD monitor 27.
[0011]
In the camera of this embodiment, a distance measuring unit 30, a photometric unit 31, and a strobe light emitting unit 32 are provided, and a distance measuring operation, a photometric operation, and auxiliary light irradiation can be performed under the control of the microcomputer 10. The microcomputer 10 is connected to a power supply circuit 33, an LCD display unit 34 for displaying the number of shots and other shooting information, and a backlight drive circuit 36 for driving a backlight 35 of the LCD monitor 27. 10 to control. Further, the microcomputer 10 includes a power switch 41, a release half-press switch 43 operated by operating the release button 42, a release full-press switch 44, a mode selection switch 45, and a zoom up switch operated by operating the zoom button 46. 47, a zoom-down switch 48, and an imaging data erasure switch 49 are connected to each other, and the microcomputer 10 is configured to perform necessary control by turning on and off these switches.
[0012]
The photographing operation of the camera having the above configuration will be described with reference to the flowchart of FIG. First, when the power is turned on (S11), the microcomputer 10 determines the state of the mode selection switch 45 (S12) and sets the selected photographing mode. Here, a normal shooting mode M1 for shooting on the photosensitive film while visually checking the subject with the optical viewfinder 11, an electronic monitor shooting mode M2 for shooting on the photosensitive film while checking the subject with the LCD monitor 27, and the LCD A digital shooting mode M3 for recording shooting data in the flash memory 23 while checking the subject on the monitor 27, and a dual shooting mode M4 for shooting on the photosensitive film and digital shooting in the same manner as described above while checking the subject on the LCD monitor 27. And can be selected.
[0013]
In the normal photographing mode M1, the microcomputer 10 stops the image pickup operation by the CCD element 14 by the CCD drive circuit 15. For this reason, the photographer looks into the optical viewfinder 11 to check the subject, and operates the release button 42 to photograph the photosensitive film 8. At this time, when the release half-press switch 43 at the release button 42 is turned on, the distance measurement circuit 30 performs distance measurement and the photometry circuit 31 performs light measurement, and when the release full-press switch 44 is turned on, the aperture driving circuit 7 and the shutter drive. The circuit 6 operates to execute photographing. Further, when the zoom button 46 is operated during photographing and the zoom-up switch 47 or the zoom-down switch 48 is turned on, the zoom mechanism 3 of the photographing lens 1 operates to zoom the photographing lens 1 and detect the focal length. While the focal length of the photographing lens 1 is detected by the unit 2, the focal length of the photographing lens 1 is changed by feedback control, and the optical viewfinder 11 is zoomed in conjunction with this. Thus, the photographer can photograph on the photosensitive film 8 while confirming the photographing angle of view accompanying the zoom operation of the photographing lens 1 with the optical viewfinder 11 (S13).
[0014]
In the digital photographing mode M 3, the microcomputer 10 drives the CCD element 14 by the CCD drive circuit 15, and the image processing signal photographed by the CCD element 14 through the optical system of the optical finder 11 is processed in the signal processing unit 16. That is, the imaging signal is suppressed in the CDS circuit 17 and converted into a digital signal by the A / D converter 18 to obtain imaging data. Further, a predetermined process is executed through the first field memory 19, the signal processing circuit 20, and the second field memory 21, and then output as a video signal from the D / A converter 22 and captured on the LCD monitor 27. Is displayed. At this time, when the release button 42 is operated, the microcomputer 10 compresses the image data of the imaging screen in the signal processing circuit 20 and stores it in the flash memory 23 (S14). The stored imaging data can be displayed as an image on the LCD monitor 27 at any time. In this digital photographing mode M3, it is possible to perform photographing by zooming the optical finder 11 by operating the zoom button 46, but in the state before the release button 42 is operated, the signal processing circuit 20 The electronic zoom circuit 25 performs an electronic zoom process, and an image obtained by the electronic zoom process is displayed on the LCD monitor 27. This electronic zoom process will be described in the next electronic monitor photographing mode M2.
[0015]
In the electronic monitor photographing mode M2, the image pickup signal picked up by the CCD element 14 is electronically zoomed by the electronic zoom circuit 25 of the signal processing circuit 20 and displayed on the LCD monitor 27 as a video signal. For example, as described in Japanese Patent Laid-Open No. 5-83612, the electronic zoom circuit 25 enlarges image data in order to display at a zoom magnification corresponding to the focal length of the taking lens 1. Only the portion to be displayed is read out from the field memory, the number of scanning line interpolations corresponding to the zoom magnification is performed, and a video signal is generated based on the imaging data having a predetermined number of scanning lines by this interpolation. By displaying on the monitor image, it is possible to obtain a monitor image in which the screen is enlarged in the horizontal and vertical directions. For example, by selecting a part of the imaging data in the first field memory 19 of FIG. 4A and enlarging it as shown in FIG. 4B and displaying it on the LCD monitor 27, the electronic zoom process is performed. Realized. In the case of the camera of this embodiment, when the photographer operates the zoom button 46 at the time of shooting, the zoom operation of the taking lens 1 and the zoom operation of the optical viewfinder 11 linked thereto are not performed immediately, and the microcomputer 10 Detects and holds the focal length set by the zoom button 46 (hereinafter referred to as the set focal length) from the state of the zoom-up switch 47 and the zoom-down switch 48 when the zoom button 46 is operated. Then, the microcomputer 10 controls the electronic zoom circuit 25 built in the signal processing circuit 20 based on the set focal length thus held, and as described above, the LCD monitor 27 has the zoom magnification corresponding to the set focal length. Display monitor video. Then, in the case of specific conditions as described later, or when the photographer operates the release button 42 while confirming the LCD monitor image corresponding to the set focal length, the microcomputer 10 quickly sets the taking lens 1 to the set focal length. Zooms up to. Simultaneously with the completion of this zoom operation, the shutter drive circuit 6 performs photographing on the photosensitive film 8 (S13).
[0016]
The operation of the electronic monitor photographing mode M2 will be described in detail with reference to the flowchart of FIG. That is, as described with reference to the flowchart of FIG. 3, when the mode selection switch 45 determines that the electronic monitor photographing mode M2 is selected, the microcomputer 10 starts displaying the monitor image on the LCD monitor 27 (S101). m = 0 is set (S102). Then, the set focal length is detected from the state of the zoom button 46 (S103), and the detected set focal length is held in, for example, a register. Next, the current focal length (hereinafter referred to as the current focal length) of the photographing lens 1 detected from the focus detection unit of the zoom mechanism 3 is compared with the set focal length held (S104), and the set focal length is determined. Is shorter than the current focal length, that is, under the specific condition that the focal length of the taking lens 1 is set to the wide-angle side with respect to the current focal length, the zoom driving circuit 4 determines the focal length of the taking lens 1. The set focal length is set (S105). Thereby, the focal length of the optical finder 11 is also set to a focal length corresponding to the set focal length. In step S104, if the set focal length is larger than the current focal length, this zoom drive is not performed, and the electronic zoom circuit 25 is driven to electronically process the image pickup signal of the CCD element 14, and this electronic zoom is performed. The subject image is enlarged by the processing, and a monitor image corresponding to the set focal length is displayed on the LCD monitor 27 in a telephoto state in which the apparent focal length is increased (S106).
[0017]
The microcomputer 10 monitors the state of the release half-press switch 43 (S107). When the release half-press is detected by operating the release button 42, the microcomputer 10 drives the distance measuring circuit 30 and the photometry circuit 31 to measure the distance measurement data dm. And photometric data fm are obtained (S108). Next, the release full-press switch 44 determines whether the release is fully pressed (S109). When the release full-press is detected, the zoom drive circuit 4 sets the focal length of the photographing lens 1 to the set focal length (S110), and the setting. Based on the focal length, shooting is performed as described later (S120). On the other hand, if the release full press is not detected in step S109, D2 = dm is set based on the distance measurement value dm (S111), and it is determined whether m = 0 (S112). When m = 0, the distance measurement value dm is set to D1 = dm (S113). When m is not 0, the distance measurement value of D1 holds the value dm when m = 0. Then, it is determined whether the distance difference between D2 and D1 is smaller or larger than 50 cm (S114). If this distance difference is larger than 50 cm, it is determined that the photographer has turned the object to be photographed to a different object, Then, m = 0 is set (S115), and the process returns to step S107, and the same flow is repeated at a predetermined extremely short time interval.
[0018]
On the other hand, if the distance difference between D2 and D1 is smaller than 50 cm in step S114, it is determined that the photographer is shooting the same subject, and the number of repetitions of the flow, that is, m is a preset number value M. It is determined whether it is equal to (here, M = 5) (S116). If m is not M, 1 is added to m (S117), and the process returns to step S107. This flow is repeated five times until m = M (= 5). If m = 5 and there is no change even after five repetitions, the zoom drive circuit 4 is controlled as having a high probability of shooting. Then, the zoom mechanism 3 performs a zoom operation so that the photographing lens 1 has a set focal length (S118).
[0019]
When a full press of the release button 42 is detected (S119), exposure control based on the photometric value fm is performed in the aperture drive circuit 7, and the photosensitive film is taken by the photographic lens 1 by the shutter operation by the shutter drive circuit 6. 8 is executed (S120). At this time, the imaging data is recorded in the second field memory 21, converted into an analog signal by the D / A conversion circuit 22 and output as a video signal, and the monitor video is frozen (determined) on the LCD monitor 27 ( S121).
[0020]
In the dual shooting mode M4, the electronic monitor shooting mode M2 and the digital shooting mode M3 are simultaneously performed, whereby shooting 13 on the photosensitive film and recording S14 in the imaging data memory are performed. Each photographing and recording operation is the same as that in each of the modes M2 and M3, and the description thereof is omitted here.
[0021]
As described above, in the camera of the present embodiment, in the electronic monitor photographing mode M2 and the digital photographing mode M3, except for the case of specific conditions, that is, the case of performing photographing at a wide angle shorter than the current focal length. Since the subject image displayed on the LCD monitor 27 is an image zoomed by the electronic zoom in the electronic zoom circuit 25, the photographer operates the zoom button 46, and the zoom magnification corresponding to the set focal length is set. It becomes possible to monitor the subject. When the release button 42 is operated while observing the LCD monitor 27, the photographing lens 1 and the optical viewfinder 11 are immediately driven to the set focal length by the zoom mechanisms 3 and 12 under the control of the microcomputer 10, so that the set focus is set. In the case of photographing at a distance, that is, in the electronic monitor photographing mode M2, a photosensitive operation to the photosensitive film 8 is performed, and in the digital photographing mode M3, photographing with the CCD element 14 is performed. Therefore, the zoom mechanisms 3 and 12 of the photographic lens 1 and the optical viewfinder 11 are not operated until immediately before shooting, and the power consumption of the zoom mechanisms 3 and 12 during that time can be reduced and battery consumption is suppressed. It becomes possible to do.
[0022]
In the present embodiment, in steps S107 to S113 of the process, the distance measurement number value m is counted while counting from the time when the release button 42 is half-pressed, and the distance measurement number value m is a predetermined number M. When the zoom lens 46 is reached, it is considered that the photographer has a high probability of photographing the subject, and the zoom mechanisms 3 and 12 of the photographing lens 1 and the optical viewfinder 11 are driven to set the focal lengths to the focal lengths set by the zoom buttons 46. Therefore, when the release button 42 is fully pressed, it is possible to shorten the time until the photographing lens 1 is set to the set focal length, and to realize a release operation with high responsiveness. This responsiveness is the same in the digital photographing mode.
[0023]
Here, in the above-described embodiment, the case where each zoom mechanism of the photographing lens and the optical finder is mechanically operated is described. However, an independent zoom mechanism is provided for each of the photographing lens and the optical finder, The present invention can be similarly applied to a camera having a configuration in which the focal length of each can be set individually. In this case, while the zoom operation of the photographic lens is stopped, only the optical finder may be zoomed, and the subject actually zoomed by the CCD element is imaged and displayed on the LCD monitor. Therefore, the electronic zoom circuit can be omitted. However, since the zoom operation in the optical viewfinder cannot be stopped except during photographing as in the above-described embodiment, the above-described embodiment is more advantageous in terms of reducing power consumption. The present invention is also applicable to an LCD monitor type single-lens reflex camera in which a subject image formed by a photographic lens is guided to an optical finder to form a finder image, and a CCD element is incorporated in the optical system of the photographic lens. Is possible.
[0024]
【The invention's effect】
As described above, according to the present invention, the subject image is displayed on the monitor at a zoom magnification corresponding to the focal length set by the focal length setting means at the time before photographing, so that the zoom mechanism of the photographing lens is driven. The photographing angle of view of the subject can be confirmed without any trouble, and at the time of photographing, photographing with the photographing lens can be realized at the focal length set by the focal length setting means. For this reason, it is not necessary to operate the zoom mechanism of the photographing lens or the optical finder until immediately before photographing, and the power consumption in the zoom mechanism in the meantime, especially the power consumption in the zoom mechanism of the photographing lens having a large amount of consumption can be reduced. It is possible to suppress the consumption of the battery installed in the camera, and to obtain an effect that can extend the shooting life of the camera. Further, the distance measurement is performed a plurality of times during photographing, and when the distance measurement data is within a predetermined range, the photographing lens is immediately set to the focal length set by the focal length setting means so that the photographing lens has a predetermined focal point. Release timing with high responsiveness can be realized by advancing the timing set for the distance.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of a camera of the present invention.
2 is a schematic perspective view showing a configuration of a photographing lens and an optical viewfinder of the camera of FIG. 1. FIG.
FIG. 3 is a flowchart showing an outline of an imaging mode and an operation in each mode.
FIG. 4 is a diagram for explaining an operation of an electronic zoom.
FIG. 5 is a flowchart for explaining an operation in an electronic monitor photographing mode.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shooting lens 2 Focal length detection part 3 Zoom mechanism 4 Zoom drive circuit 5 Focus circuit 6 Shutter circuit 7 Aperture drive circuit 8 Photosensitive film 10 Microcomputer 11 Optical finder 14 CCD element 16 Signal processing part 20 Signal processing circuit 25 Electronic zoom circuit 27 LCD Monitor 42 Release button 46 Zoom button

Claims (5)

A photographing lens including a zoom mechanism for capturing a subject, the focal length setting means for setting the focal length by controlling the pre-Symbol zoom mechanism, corresponding to the focal length set by the focal length setting means In a zoom type camera comprising a monitor device for displaying the subject at a zoom magnification, means for setting the photographing lens to a focal length set by the focal length setting means by the zoom mechanism during a photographing operation; Distance measuring means for measuring the object, means for repeatedly detecting the distance measurement data by the distance measurement means, the number of detections of the distance measurement data reaches a predetermined number, and the distance measurement data is within a predetermined range when located within, and means for setting the focal length is set by the immediately the focal length setting means the photographing lens by the zoom mechanism Zoom camera, wherein the door.   An image sensor disposed in one of the optical systems of the photographing lens or an optical finder provided independently of the photographing lens, and an image signal obtained by imaging with the image sensor, A signal processing circuit to be displayed as an image on a monitor device, the electronic signal processing circuit including an electronic zoom circuit for performing an electronic zoom process on an image pickup signal obtained by the image sensor and displaying the image on the monitor device. 2. The zoom camera according to claim 1, wherein the zoom circuit is configured to control the monitor image to a zoom magnification corresponding to the focal length set by the focal length setting means.   The taking lens and the optical viewfinder are each provided with a zoom mechanism, and the zoom mechanisms of the taking lens and the optical viewfinder are driven in conjunction with each other to set the respective focal lengths, and the imaging device forms an image with the optical viewfinder. The zoom camera according to claim 2, wherein a captured subject image is captured. Said means for detecting the distance measurement data, according to claim 1 The zoom camera as defined in any one of the three release button and performs the detection operation at predetermined time intervals when the half-pressed state. The focal length setting means drives the zoom mechanism when the focal length shorter than the current focal length of the photographic lens is set by a zoom operation, and sets the photographic lens and the optical finder to the set focal length. The zoom type camera according to claim 1 , wherein the zoom type camera is set as follows.

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