JPS63318531A - Electric zoom camera - Google Patents

Abstract

PURPOSE:To simply execute inter-exposure zooming in various zooming formats by providing the titled camera with a driving speed determining means for determining the driving speed of a motor in accordance with a set shutter second. CONSTITUTION:When the set shutter second Tv is inputted to the driving speed determining means 1, the means 1 determines the driving speed of a zoom motor 3 corresponding to the shutter second Tv and sends the signal to a drive control circuit 2. The circuit 2 drives the motor 3 at a driving speed corresponding to the shutter second Tv in response to a release start signal. Consequently, any person can simply execute sure and various inter-exposure zooming in accordance with the shutter second only by selecting an inter-exposure zooming mode and executing normal photographing operation (the depression of a release button, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric zoom camera, and more particularly to an electric zoom camera in which zooming is performed by a motor.

[Prior Art] One of the means for photographic expression is inter-exposure zooming. This method performs zooming while the shutter curtain is open for exposure, and attempts to create a dynamic photograph by capturing the enlargement or reduction process caused by zooming. However, even if a photographer who is not very skilled with a camera tries to take a picture using this technique, there are problems such as the camera shaking during zooming or the shutter speed and zooming timing not matching properly.

Therefore, a technique for performing zooming during exposure using a motor or the like is disclosed in Japanese Patent Laid-Open No. 61-228426. According to the technology disclosed in this publication, during normal shooting, exposure is performed by operating the release button, but when the during-exposure zoom mode is selected using the mode button,
Operate the mode button to zoom to the telephoto side, operate the mode button again to start zooming,
Next, exposure is started.

[Problems to be Solved by the Invention] Therefore, although it is better than performing all zooming manually, it is undesirable that the release operation differs depending on the mode, and there is a problem that only uniform zooming is possible. .

In view of these problems, the purpose of the present invention is to improve the inter-exposure zooming technique, which has conventionally been based on human intuition and experience.
To provide an electric zoom camera that allows anyone to easily perform zooming in various forms.

[Means and effects for solving the problems] In the electric zoom camera of the present invention, as shown in a conceptual diagram in FIG. The drive speed determining means 1 determines the drive speed of the zoom motor 3 according to the shutter time Tv, and sends this signal to the drive control circuit 2. When the drive control circuit 2 receives the output of the drive speed determining means 1, it drives the zoom motor 3 at a drive speed corresponding to the shutter time Tv in response to the release start signal.

[Embodiment] FIG. 2 is a block circuit diagram of an electric zoom camera showing an embodiment of the present invention. The electric circuit of this electric zoom camera is broadly composed of a main body circuit 10° lens circuit 30 and a strobe circuit 50.

In the main circuit 10, a main CPU (central processing unit) 11 controls the sequence of the entire system and performs various calculations. The release switch 12 is a two-step stroke switch, and when the first step of the release switch 12 is detected, the main CPU 1 starts AF (autofocus) operation, and the second step of the release switch 12 is detected. and the main CPU II starts the exposure sequence. The mode setting switch 13 is an input switch for setting various exposure modes and for setting conditions for zooming during exposure according to the present invention. The focus detection circuit 14 captures the image produced by the focus detection optical system using a photoelectric conversion element such as a CCD (charge-coupled device), converts the output into A/D, and then sends the image to the main CPU.
Send to I 1. Based on this data main CPUI 1
detects the amount of defocus and its direction. A winding control circuit 15 winds the film and charges the shutter mechanism based on signals from the main CPU II. The film sensitivity reading circuit 16 reads the DX code of the film and sends a signal of film sensitivity information Sv to the main CPU 11. The photometric processing circuit 17 detects the subject brightness from the photocurrent of a photometric element 18 such as a silicon blue cell, and sends a signal indicating the subject brightness By.

The aperture control circuit 19 performs lens aperture control during UP/DOWN control of the quick return mirror based on a signal corresponding to the aperture value Av calculated by the main CPU II. The shutter control circuit 20 creates a shutter time based on a signal corresponding to the exposure time Tv from the main CPU II,
Controls the front and rear curtains of the focal plane shutter. Then, a running start signal for the leading curtain and trailing curtain is sent to the strobe control CPU 51 of the strobe circuit 50 for strobe control. The display circuit 21 displays the exposure time TV calculated by the main CPU II, the aperture value Av, AF in-focus/out-of-focus, and mode setting status.

In the lens circuit 30, the lens control CPU 31
Based on the instructions from the main CPU II, the zoom motor 33 necessary for zooming during exposure is controlled, and the AF mode control 35 is controlled based on the defocus amount calculated by the main CPU II.The zoom motor drive circuit 32 controls the lens control C
The control signal of the PU 31 is amplified to the power necessary to drive the zoom motor 33 , and the AF motor drive circuit 34 amplifies the control signal of the lens control CPU 31 to the power necessary to drive the AF motor 35 . The zoom motor drive circuit 32 is, for example, a well-known motor drive circuit constituted by a bridge circuit of transistors Q1 to Q4, as shown in FIG. The AF motor drive circuit 34 also has a similar configuration. The pulse generation circuit 36 generates pulses according to the rotational speed of the AF motor 35 and sends them to the lens control CPU 31 . This pulse generating circuit 36 is composed of, for example, a slit plate 41 rotated by an AF motor 35 and a photointerrupter 42, as shown in FIG. Also, lens control C
The PU31 sends the lens data necessary for the main CPU II to calculate the above Av and Tv and the absolute distance data necessary for flashmatic control of the strobe to the main CPU.
Send to II. The absolute distance encoder 37 sends absolute distance data indicating the subject distance to the lens control CPU 31 during focusing.
The zoom encoder 38 sends changes in lens focal length due to zooming to the lens control CPU 31. As shown in FIG. 4, this zoom encoder 38 consists of a circuit pattern 45 provided on a fixed frame 43 and a zoom ring 44.
When the driving force of the zoom motor 33 is transmitted to the zoom ring 44 via gears 47a and 47b and the zoom ring 44 rotates, the conductive contact piece 46 slides on the circuit pattern 45 to change the focal length. Absolute distance encoder 3
7 also has approximately the same configuration, and the driving force of the AF motor 35 is transmitted to the distance ring 49 via the gear 48.
By rotating 9, the object distance is output as an absolute distance.

In the strobe circuit 50, the strobe control CPU 51 controls the drive of the booster circuit 52 and controls the cyrisks 54 and 55 in various light emission modes via the light emission control circuit 53 based on instructions from the main CPU II. A diode 56 connected to the booster circuit 52 is for rectifying the output of the booster circuit 52. A resistor 57 connects the power supply line 11 of the booster circuit 52 and the ground line g when the thyristor is turned on. It has the function of preventing short-circuits between the capacitors 58 and accumulating trigger charges in the capacitor 58. The charge in the capacitor 58 flows instantaneously when the thyristor 54 is turned on, and due to the voltage change on the primary side of the trigger transformer 59 at this time, a high voltage necessary to cause the flash discharge tube 60 to emit light is generated on the secondary side. The main capacitor 61 stores energy for the flash discharge tube 60 to emit light. Flash discharge tube 60
A capacitor 62 in series with the main capacitor 61 is a useful capacitor in the multi-light emission mode, and prevents the charge of the main capacitor 61 from being completely consumed by one light emission of the flash discharge tube 60. The thyristor 55 discharges the charge in the capacitor 62 and prepares for the next light emission. Further, this thyristor 55 is turned on in synchronization with the turning on of the thyristor 54 when the strobe is full-emitting light, thereby killing the function of the capacitor 62 and causing the charge in the main capacitor 61 to emit light at once.

Here, the operation of the strobe circuit 50 during multi-light emission will be explained in the fifth section.
This will be explained using figures. By applying a gate voltage to the thyristor 54 by the light emission control circuit 53 and temporarily turning on the thyristor 54, the trigger transformer 59 applies a high voltage to the trigger electrode of the flash discharge tube 60, causing the discharge tube 60 to start emitting light. let As a result, the electric charge of the main capacitor 61 is instantaneously discharged, so that the potential of the main capacitor 61 decreases, but the flash discharge tube 60
Because of the capacitor 62 connected in series with the capacitor 62, light emission stops when the sum of the potential of the capacitor 62 and the light emission stop voltage of the flash discharge tube 60 matches the potential of the main capacitor 61, and the drop in the potential of the main capacitor 61 stops. . Therefore, as the charge of the main capacitor 61, again,
Energy that can emit light remains. However, the light cannot be emitted again if the charge remains in the capacitor 62, so after the light emission ends, the light emission control circuit 53 applies a gate potential to the thyristor 55 to temporarily turn on the thyristor 55 and discharge the charge in the capacitor 62. As a result, the voltage of the capacitor 62 becomes Ov at once, and a state becomes possible where light can be emitted again. In this way, by alternately controlling the thyristors 54 and 55 of the strobe circuit 50, a plurality of light emissions can be performed until the potential of the main capacitor 61 drops to the light emission stop voltage of the flash discharge tube 60.

Next, the program of the main CPU 1l will be explained with reference to the flowchart shown in FIG. When the camera is powered on, the main CPU 1 performs a power-on reset and initialization is performed. Next, the main CPU 1l reads various modes from the mode setting switch 13. When reading this mode, settings such as the during-exposure zoom mode and strobe light emission mode are performed.

In this embodiment, four types of zooming modes are arbitrarily set as the during-exposure zooming mode setting by the mode setting switch 13. In other words, the four types of zooming modes are as shown in FIG.
Zooming mode ZM1 monotonically starts zooming from the W end (hereinafter abbreviated as W end) and reaches the telephoto end (hereinafter abbreviated T end), and conversely, zooming monotonically starts from the T end and reaches the W end. The zooming mode ZM2 and the two normal zooming modes ZMl.

Each corresponds to 2M2, and each has a W end.

Two zooming modes Z: Start zooming from the T end and reach the other end, but even if a zooming start signal is received, zooming will stop for a certain period of time and then start zooming.
M a , Z M 4. The latter zooming mode ZM3. When ZM4 is set, the subject at the stop motion position becomes stationary, and the subject at the same position is more emphasized and clearly exposed.

Further, the strobe light emission mode set by the mode setting switch 13 can be set only when the shutter speed is slower than the strobe synchronization speed. As mentioned above, there are two types of strobe light emission modes: the normal light emission mode that uses one flash discharge, and the multi-flash mode that repeats light emission several times during exposure. There is a front curtain light emission mode in which light emission is triggered at the time of completion of travel, and a rear curtain light emission mode in which light emission is triggered at the time the shutter trailing curtain starts traveling.

In the during-exposure zooming mode, you can also select and set any of the above flash modes. In this case, the strobe synchronization inter-exposure zooming mode will be set, and the strobe will not fire during zooming. becomes possible.

FIG. 11 shows the light emission trigger point in the front curtain light emission mode and the rear curtain light emission mode. FIG. 12 shows one light emission trigger point in the multi-light emission mode. In the case of multi-flash mode, the number of flashes is also set by the mode setting switch 13.
Set by.

To continue the explanation by returning to the flowchart of FIG. 6 again, after reading various modes from the mode setting switch 13, the main CPU II receives the By value indicating the subject brightness from the photometry processing circuit 17 and the By value from the film reading circuit 1δ. Read the Sv value indicating sensitivity. Next, the lens control CPU
31 and read various information about the lens attached.

Then, based on this data, a program diagram is determined, and the shutter time Tv and aperture value Av are calculated. This calculated value is output to the display circuit 21 and displayed. Furthermore, when zooming during exposure, multi-light emission, etc. are not possible with the calculated Tv value, this is also displayed. Next, strobe control C
It communicates with the PU 51 and sends a strobe charge signal when the brightness requires strobe light emission or when light emission is requested during zooming during exposure.

Next, it is determined whether the first step of the release switch 12 is pressed, and if it is not pressed, the process returns to the beginning of the flow to read the mode setting switch 13 again. When it is determined that the first step of the release switch 12 is pressed, the routine goes to a distance measurement routine to perform AF. In this distance measurement routine, the main CPU 11 uses data from the focus detection circuit 14 to determine the defocus amount and AF.
The driving direction of the motor 35 is calculated. Next, it is determined whether distance measurement is possible. Here, it is determined whether or not to continue distance measurement by determining the contrast of the subject and determining whether the number of distance measurements has reached a specified value. When it is determined that distance measurement is not possible, the display circuit 21 displays an out-of-focus display and returns to the beginning of the flow. When it is determined that distance measurement is possible, it is then determined whether the defocus amount is within the focusing range. When it is determined that the focus is out of focus, the lens control CPU 3
1, the AF motor 34 is driven, and after receiving a signal indicating the completion of driving, the process returns to the II distance routine in order to make focus determination again. When the focus is determined, the display circuit 21 displays the focus.

Next, it is determined whether the release switch 12 has been pushed further from the first step to the second step. When it is determined that the second step is pressed, the routine goes to the N output control routine. Then, the Bv value and Sv value are read by the n1 light processing circuit 17 and the film sensitivity reading circuit 16. Next, communication is performed with the lens control CPU 31, and if the during-exposure zoom mode is selected, the lens control CPU 3 transmits the conditions that match the selected during-exposure zoom mode.
1 to prepare for zooming. On the other hand, the main CPU II determines a program diagram based on data from the lens control CPU 31, and determines the final Av value and Tv value.
Calculate the value. Thereafter, it communicates with the strobe control CPU 51 and sends the light emission mode conditions to the same CPU 51. Next, the calculated Av value is set to the aperture control circuit 19 and a start signal is sent. Then, the aperture control circuit 19 raises the mirror and narrows down the aperture to the set Av value. After narrowing down, the main CPU II sets the calculated Tv value to the shutter control circuit 20 and sends a start signal. In addition, the shutter control circuit 20
At the same time as issuing the start signal, the lens control CPU 31
A Tv start signal is sent as a signal to start zooming. The shutter control circuit 20 controls the front curtain and rear curtain based on the set Tv value, and sends start signals for the front curtain and rear curtain to the strobe control CPU 51 for use as a strobe light emission trigger.

When the shutter control ends, a shutter control end signal is sent to the main CPU II. Based on this shutter control end signal, the main CPU II
9 Hemira sends a descending signal and finishes exposure control. After this, a winding start signal is sent to the winding control circuit 15 in preparation for the next photographing. This signal causes the film to be wound up and the shutter mechanism to be charged at the same time. The operation of the main CPUI 1 then returns to the beginning of the flow.

Next, according to the flowchart shown in FIG. 7, the lens control CP
The program of U31 will be explained. When the camera is powered on, power is also supplied to the lens circuit 30, and the lens control CP
U31 performs a power reset and is initialized. Next, the lens control CPU 31 enters a state of waiting for a communication request from the main CPU 1. When a communication request signal is received, the lens control CPU 31 sends photographing lens data to the main CPU II. This data includes a lens focal length, a lens F number, an identification signal as to whether it is a single lens or a zoom lens, the maximum speed of the zoom motor 33, etc. On the other hand, the main CPU 1 sends the mode setting state, a signal requesting driving of the AF motor 35, and a defocus tilt Tv value. Next, the lens control CPU 31 determines whether there is a signal requesting driving of the AF motor 35.

When there is a request signal, the defocus amount calculated by the main CPU II is converted into the number of pulses of the pulse generation circuit 36 representing the entire drive of the AF motor 35. Then, the AF motor 35 is driven by the number of pulses. When the driving of the AF motor 35 is completed, a driving end signal is sent to the main CPU 1. And again main CPUI 1
It enters a state where it waits for a communication request signal from.

When there is no signal requesting driving of the AF motor 35, it is then determined whether the during-exposure zooming mode is requested. If no request has been made, the main CPU II has simply made a communication request to obtain the lens data necessary for calculating the Av value and Tv value. Therefore, the lens control CPU 31 is in a state of waiting for a communication request until the next communication request arrives.

If the during-exposure zoom mode is selected, first the during-exposure zoom mode is set to the normal zoom mode ZM.
,, it is determined whether ZM2 (see FIG. 9) is the zooming mode ZM3°2M4 (see FIG. 9) with stop motion. Whichever step is to be taken next, the zoom ring 44 is initialized to either the T end or the W end based on the signal from the main CPU II.

That is, if zooming mode ZMl or ZM3 is selected, no matter where the focal length of the zoom lens is at this time, it will be zoomed to the W end and will be in a standby state.
When the zooming mode ZM2°2M4 is selected, the camera is zoomed to the T end and enters a standby state.

When the mode setting switch 13 is set to the normal zooming mode, the driving speed of the zoom motor 33 is simply calculated from the Tv value. For example, if zooming mode zM2 shown in FIG. 9 is selected as the normal zooming mode, as shown in FIG.
The shutter curtain is opened in advance so that the shutter time t (Tv) is greater than or equal to TVO, the shutter time TWO, TVI, TV.
2, this zooming mode ZM2
The zooming speed is ZM zM 2M2
It is controlled by the speed characteristics of 220' and 21'. However, if the shutter time Tv is faster than the shutter time TVO according to the maximum zooming speed characteristic Z M 20, that is, T
In the case of VI<TVO, zooming is basically performed from the T end by the control system of the speed characteristic zM2o, but since the shutter time Tv is TVm, the focal length f is zoomed from the T end to the W end. The change is up to the focal length fm.

Returning to the flow shown in FIG. 7, after calculating the normal zooming speed, the CPU waits for a Tv start signal, which is a zooming start signal, from the main CPU II. TV
When the start signal is received, the zoom encoder 38 drives the zoom motor 33 to the W end at the above drive speed when the lens is at the T end, and to the T end when the lens is at the W end.

When the normal zooming drive is completed, the device waits for a communication request signal until the next signal arrives. During zooming with stop motion, the lens control CPU 31
A time period during which the zoom motor 33 is not driven is determined in accordance with the v value, and a timer is set. Then, the driving speed of the zoom motor 33 is calculated in accordance with the rest time. Next, a Tv start signal is waited for, and when the start signal is received, a still timer is started, and the zoom motor 33 is driven after delaying the start of zooming by a certain period of time set by the still timer. The subsequent movement is similar to that during normal zooming, and the zoom motor 33 is driven at a zooming speed according to the Tv value. In this case as well, when the Tv value is faster than the preset seconds, the drive speed of the zoom motor 33 is at its maximum, but the entire focal length range is not necessarily zoomed.

Here, drive speed control of the zoom motor 33 according to the Tv value will be explained again. The relational expression between the rotational speed N (rps) of the zoom motor 33 and the time t is as shown in the following equation (1).

N-No (1-e70) (1) However, No is the steady rotation speed (rps), and τ. is the time constant of the system.

When the above equation (1) is integrated with respect to time, the following equation (2) is obtained, which is t since the zoom motor 33 starts rotating.
It shows the cumulative number of revolutions after seconds.

-N t+N τ e -N oτ1...
...(2) Here, S moves the zoom ring 44 from the T end to the W end (or from the W end to the T end).
It is assumed that this is the amount of rotation of the zoom motor 33 necessary to drive the zoom motor 33 to the end). The steady rotation speed of the zoom motor 33 is
Approximately, it is proportional to the applied voltage v2. therefore,
If the constant of proportionality is K, then N o ” K V z ・・・・・・・・・(3)
Therefore, when formula (3) is substituted into the above formula (2) and solved for the applied voltage Vz, the following is obtained. From this equation (4), shutter time t and rotation amount S,
τ, which is a constant specific to the motor. Once this is determined, the necessary applied voltage v2 will be determined. As a method of controlling the applied voltage v2, for example, a method is adopted in which the voltage is varied by the ratio of the on time t to the off time t2 of the zoom motor 33. The applied voltage V at this time is the power supply voltage V
. Then, it is expressed by the following equation (5).

Vz = -Vo (5) t1
+12 By the way. Determining the applied voltage Vz using the above equation (4) is not preferable because it causes a delay in control time. Therefore, a solution corresponding to each Tv value of the above equation (4) is obtained in advance, and tt and t2 corresponding to this solution are stored in the memory in the lens control CPU 31. Then, based on the motor drive circuit 32 shown in FIG. 3, the operations from zooming speed calculation to zoom motor drive in FIG. 7 are performed.

From this <zooming speed calculation><zoom motor drive>
A detailed program of the routine up to this point is shown in FIG.

In the flow shown in FIG. 13, the shutter time Tvml~1
The on time t and the off time t2 of the zoom motor 33 are set corresponding to /30, and the zooming speed is determined by the duty ratio (t/(t1+t2)). When the shutter speed is faster than Tv -1730, it is set to t2-0, and the zooming speed is set to full speed (maximum speed) driving. Once the zooming speed is set, the zoom motor 33 is driven after waiting for a Tv start signal and determining the zooming drive direction. When the zooming drive direction is from the T end to the W end, transistors Ql and Q4 of the motor drive circuit 32 are turned on, transistors Q2 . After the zoom motor 33 is timer driven for the set time 11 with Q3 off, all transistors Q1 to Q4 are turned off and the same state is measured for the set time t2. This on/off state is repeated until the W end is reached. Further, when the driving direction is from the W terminal to the terminal terminal, the transistor Q1. Q4 is off, transistor Q2. It is the same as in the case of the drive direction above, except that Q3 is in the on state, and the zoom motor 3 is turned on until it reaches the T end.
3 repeats turning on and off in the same way.

The driving speed of the zoom motor 33 is controlled not only by the duty ratio of the on time tl and the off time t2 as in this embodiment, but also by changing the voltage value based on the above equation (4). It's okay.

Next, according to the flowchart in Fig. 8, the strobe control CPU
51 programs will be explained. When the strobe circuit 50 is powered on, the strobe control CPU 51 performs a power-on reset and initialization is performed. and main CPUI
It enters a state of waiting for a communication request from I. When a communication request comes, the strobe control CPU 51 performs data communication with the main CPU II. Then, the main CPU II sends the Tv value, which is data for the strobe light emission mode, and a charge signal for determining whether or not to drive the booster circuit 52. Determine whether it is present or not. If there is no charge signal, it means that the strobe is not required, so the device waits for a communication request until the next data arrives. When there is a charge signal, the strobe control CPU 51 supplies power to the booster circuit 52 to prepare for light emission.

Next, the strobe control circuit 51 determines what is requested as the strobe light emission mode.

The conditions that require the flash mode are Main C
Either the PUI 1 has determined that the subject brightness is bright enough to require flashing, or the mode setting switch 13 has requested flashing during zooming during exposure, but the second shutter release has not yet been released. is not pressed and the main CPU 11 has not entered the exposure control routine, the main CPU 1 is not sending the flash mode signal, so the strobe CPU 5
1 cannot be determined as a light emission mode of front-curtain light emission, rear-curtain light emission, or multi-light emission. Therefore, the booster circuit 52 remains in operation and waits for a communication request until the next signal from the main CPU II arrives.

After the main CPU II enters the exposure control routine, if there is a charge signal and a light emission mode is requested, the requested light emission mode is determined.

When this light emission mode is the front curtain light emission mode, the strobe control CPU 51 waits for a front curtain trigger signal from the shutter control circuit 20 accompanying the completion of front curtain travel, and the front curtain trigger signal is input. and a light emission control circuit 53
A signal is issued to turn on the hethyristors 54 and 55 at the same time. When the light emission ends, the strobe CPU 51 enters a state of waiting for a communication request. Also in the trailing curtain light emission mode, the strobe control CPU 51 performs similar control based on the trailing curtain trigger signal accompanying the start of trailing curtain travel (see FIG. 11). When in multi-flash mode, first the strobe CPU5
1 is the number of flashes set by the mode setting switch 13 and T.
Calculate the interval from the v value. Next, wait for the leading curtain trigger signal, and when the trigger signal is input, the thyristor 54 is first turned on as described above, and the main capacitor 6 is turned on.
A part of the charge of 1 is caused to flow into the flash discharge tube 60 to cause it to emit light. Immediately after the light emission stops, the thyristor 55 is turned on to discharge the charge in the capacitor 62. By controlling the thyristors 54 and 55 via the light emission control circuit 53, light emission control in the multi-light emission mode is performed. When the light emission by the front curtain trigger ends, the calculated interval is set to a total of 71 on the timer! JL, performs light emission control. After emitting light a predetermined number of times, the light emission control is finally performed using the trailing curtain trigger, and the multi-light emission mode is ended (see FIG. 12).

After this, it enters a state of waiting for a communication request.

Next, another embodiment of the present invention will be described using FIGS. 14 to 16. This embodiment differs from the previous embodiment only in the flow of the lens control CPU 31, so other explanations will be omitted.

As can be seen by comparing the flow chart of FIG. 14 with the flow chart of FIG.
In this embodiment, the zoom motor 33 is controlled by selecting the optimal speed pattern for the Tv value from among the drive speed patterns of the zoom motor 33 that are prepared in advance in a plurality of patterns, which were previously "calculated" according to the v value. It is something to do. For example, in normal zooming, if the zooming mode is from the W end to the T end, if the shutter speed is on the high speed side,
Zooming is performed by controlling the zoom motor 33 according to the pattern of the zooming mode zMla shown in FIG. 15, or if the shutter speed is on the low speed side, according to the pattern of the zooming mode zMlb. In addition, in the case of stop motion zooming, for example, as in the zooming mode ZM a al Z M a b shown in FIG. The zoom motor 33 is controlled by selecting the optimum one. By configuring like this,
Although it is not possible to perform zooming control as finely as in the first embodiment, since there is no need to perform calculations, the zoom motor 3
The time lag for driving 3 can be reduced. Note that the combination with other strobes, etc. is the same as in the previous embodiment.

[Effects of the Invention] As described above, according to the present invention, anyone can easily do the following by simply selecting the during-exposure zoom mode and then performing normal photographing operations (such as pressing the release button). It is possible to perform reliable and various zooming during exposure depending on the shutter speed, and it is possible to provide a variety of image expressions.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the concept of the present invention, and FIG. 2 is a block diagram showing the concept of the present invention.
FIG. 3 is an electric circuit diagram of an example of the zoom motor drive circuit shown in FIG. 2, and FIG. 4 is a block circuit diagram of an electric zoom camera showing an embodiment of the present invention. FIG. FIG. 5 is an exploded perspective view of a part of the lens barrel showing the configuration around the encoder mounting part; FIG. 5 is a voltage waveform diagram for explaining the multi-flash operation of the strobe circuit in FIG. 2; FIG. is a flowchart explaining the program operation of the main CPU in FIG. 2, FIG. 7 is a flowchart explaining the program operation of the lens control CPU in FIG. 2, and FIG.
FIG. 9 is a flowchart explaining the program operation of the strobe control CPU in FIG. 2, FIG. 9 is a diagram showing various zooming patterns in the during-exposure zoom mode read by the mode setting switch in FIG. 2, and FIG. 11 is a diagram showing how the zooming speed is set according to the shutter speed in the during-exposure zoom mode. FIG. FIG. 12 is a diagram illustrating the multi-flash emission mode of the strobe light emission mode. FIG. 13 is a flowchart illustrating an example of program operation regarding drive speed control of the zoom motor. FIG. 14 is another embodiment of the present invention. Lens control C
Flowchart illustrating the program operation of the PU, FIGS. 15 and 16 are diagrams showing various zooming patterns of the during-exposure zooming mode selected and set in the flow of FIG. 14 above. 1........ Drive speed determining means 2
・・・・・・・・・・・・・・・Drive control circuit 3.33
......Zoom motor 11...Main CPU (driving speed determining means) 31...Lens control CPU (driving speed determining means) , drive control circuit) 32...Zoom motor drive circuit (
drive control circuit)

Claims (3)

[Claims] (1) In an electric zoom camera in which zooming of a zoom lens is performed by a motor, a drive speed determining means that determines the drive speed of the motor according to a set shutter time; and a drive speed determining unit that determines the drive speed of the motor in response to a release start signal. An electric zoom camera comprising: a drive control circuit that drives the motor at a speed. (2) The electric zoom camera according to claim 1, wherein the shutter speed is a value set by an automatic exposure circuit. (3) The electric zoom camera according to claim 1, wherein the drive control circuit moves and sets the lens to a wide-angle end or a telephoto end prior to receiving the release start signal.