JP5006703B2 - Microscope imaging apparatus and imaging method for microscope - Google Patents

Description

  The present invention relates to a technique of a microscope imaging apparatus capable of capturing time-lapse imaging of an object to be observed at an arbitrary imaging interval.

  2. Description of the Related Art Conventionally, there is an imaging method called time-lapse imaging that observes a temporal change of a specimen such as a living cell in a microscope imaging apparatus. In order to observe the temporal change of the specimen by time lapse photography, it is necessary to repeatedly obtain an image of the specimen at an arbitrary photographing interval instructed by the operator.

  For example, a digital imaging device that acquires an image by exposing an imaging device such as a CCD (Charge Coupled Devices) can acquire an image at an imaging interval depending on the number of pixels read from the imaging device. In addition, when the shooting interval is sufficiently longer than the time required for still image shooting, an arbitrary shooting interval can be set by repeating still image shooting with a timing signal generated by external software or hardware.

  Japanese Patent Application Laid-Open No. 2004-228561 proposes a technique for photographing only an important section with a short photographing interval. In this case, the shooting interval is set short in response to an external trigger, and the captured frames are stored in an internal memory. Further, the frame output to the outside is delayed and output at a normal shooting interval, and the change over time of the observation target in the important section is to be confirmed in detail.

  Patent Document 2 proposes a technique for realizing an arbitrary shooting interval. Arbitrary photographing intervals are realized by changing the frequency of the clock supplied to the image sensor and the peripheral image sensor drive circuit.

  However, when an image is acquired at an imaging interval that depends on the number of pixels read from the image sensor, the image cannot be acquired at an imaging interval that is located between the imaging intervals. In addition, when repeating still image shooting using a timing signal generated by external software or hardware, set a shooting interval shorter than the time required for still image shooting, or an imaging interval located in the middle of the shooting interval depending on the number of pixels. It is difficult. Further, a delay due to the transmission time of the timing signal and the readout cycle of the image sensor occurs, and the photographing interval varies.

  In addition, as in Patent Document 1, when shooting is performed at a shooting interval shorter than normal, and frame output to the outside is delayed and output at a normal shooting interval, a memory for storing frames in the imaging device is required.

In order to arbitrarily change the frequency of the clock supplied to the image sensor and the peripheral image sensor drive circuit as in Patent Document 2, a clock generation circuit capable of outputting an arbitrary frequency and a special clock switching process are required.
JP 2003-087630 A JP 2005-175774 A

The present invention has been made in view of the circumstances as described above, without requiring additional or special hardware processing hardware, the microscope imaging apparatus and the microscope imaging how that can accurately time-lapse photography at any shooting distance The purpose is to provide.

A time lapse photography can microscope imaging apparatus for repeatedly acquiring the digital image by the desired imaging interval which is one aspect of the present invention, VD horizontal synchronizing signal to calculate the how many cycles in the capturing interval System control for obtaining a time set value and calculating the number of charge extraction pulses by calculating the number of cycles of the horizontal synchronization signal in the time from the start of shooting to the exposure start timing in order to set the exposure time within the shooting interval A synchronization signal generation unit that generates a vertical synchronization signal based on the VD time setting value output from the system control unit and the horizontal synchronization signal, and the horizontal synchronization signal as the charge extraction pulse number In order to extract the charge of the image sensor by supplying to the minute image sensor and stop the charge accumulation of the image sensor after the start of exposure, Is a configuration that includes a timing generator for generating a read pulse to synchronize immediately the synchronization signal.

Preferably, the system control unit, the period of the vertical synchronizing signal until the exposure time from the shooting start in the photographing interval is calculated how many cycles there obtains a photographing interval division value, said After the start of imaging vertical synchronization The VD time setting value is set so that the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor until the number of signal cycles is detected and becomes the same value as the imaging interval division value. After setting the number of charge extraction pulses and starting imaging, the number of periods of the vertical synchronization signal is detected and becomes the same value as the imaging interval division value until the exposure start timing, the synchronization signal generator and the timing The VD time setting value and the number of charge extraction pulses may be set so that the generation unit supplies the charge extraction pulse to the imaging device.

  Preferably, the system control unit sets the cycle of the vertical synchronization signal to a cycle determined by the number of pixels read from the image sensor, and outputs a still image shooting instruction signal from the still image shooting instruction unit in synchronization with the shooting interval. A still image shooting mode for shooting when detected, and a self-running mode in which the cycle of the vertical synchronization signal is set to the shooting interval and shooting is repeated according to the cycle of the vertical synchronization signal, It is good also as a structure which switches imaging | photography mode and self-propelled mode.

Preferably, in the still image shooting mode, when the still image shooting instruction signal is detected, the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor until an exposure start timing. A VD time setting value and the number of charge extraction pulses are set, and the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor from the completion of exposure to the imaging completion timing in the imaging interval. The VD time setting value and the charge extraction pulse number may be set.

The present invention is a time-lapse photography can microscope imaging method for repeatedly obtaining a digital image by a desired shooting intervals, obtains the VD time setting value horizontal synchronizing signal to calculate the how many cycles in the capturing interval VD time calculation step, and exposure time calculation for calculating the number of charge extraction pulses by calculating the number of cycles of the horizontal synchronization signal in the time from the start of shooting to the exposure start timing in order to set the exposure time within the shooting interval Generating a vertical synchronization signal based on the step, the VD time setting value and the horizontal synchronization signal, and supplying the horizontal synchronization signal as the charge extraction pulse to the image sensor by the number of charge extraction pulses to charge the image sensor. In order to stop the charge accumulation of the image pickup device after the extraction and the exposure start, a read pulse synchronized with the vertical synchronization signal is generated. And having a timing control step.

Preferably, the timing control step, the period of the vertical synchronizing signal until the exposure time from the shooting start in the photographing interval is calculated how many cycles there obtains a photographing interval division value, said After the start of imaging vertical synchronization by detecting the number of cycles of the signal to the same value as the imaging interval divided value, to set the charge number sampling pulse and the VD time setting value to provide the charge extraction pulse to the imaging device, imaging start After that, the VD time setting value is set so that the charge extraction pulse is supplied to the image sensor until the exposure start timing after the number of periods of the vertical synchronization signal is detected and becomes the same value as the imaging interval division value. The number of charge extraction pulses may be set.

  Preferably, in the timing control step, the period of the vertical synchronization signal is set to a period determined by the number of pixels read from the image sensor, and a still image shooting instruction signal is sent from the still image shooting instruction unit in synchronization with the shooting interval. It has a still image shooting mode for shooting when detected, and a self-running mode in which the period of the vertical synchronization signal is set to the shooting interval, and shooting is repeated according to the period of the vertical synchronization signal, It is also good to switch between the image shooting mode and the self-running mode.

Preferably, in the still image capturing mode, when the still image capturing instruction signal is detected, the VD time setting value and the number of charge extracting pulses are set so that the charge extracting pulse is supplied to the image sensor until an exposure start timing. The VD time setting value and the number of charge extraction pulses may be set so that the charge extraction pulse is supplied to the imaging device from the completion of exposure in the imaging interval to the imaging completion timing.

  According to the present invention, it is possible to perform time-lapse shooting with high accuracy at an arbitrary shooting interval without adding hardware or special hardware processing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Example 1
A microscope imaging apparatus capable of time-lapse imaging that repeatedly acquires digital images at a desired imaging interval will be described.

FIG. 1 is a block diagram illustrating a form of the first embodiment.
The microscope 1 shown in FIG. 1 and the microscope imaging apparatus 2 according to the present invention include, for example, a microscope 1 in which an electric stage that can move in a three-dimensional direction as a visual field range selection unit and a focus adjustment unit and an objective lens are opposed to each other. Has been placed. A test object is held on the electric stage, and an observation image of the test object can be visually observed with an eyepiece through an objective lens, and an imaging device 2 for a microscope provided with an imaging device (CCD). It becomes possible to image.

  The microscope imaging apparatus 2 includes an image sensor 3, a preprocessing unit 4, an A / D converter 5, a timing generation unit 6 (hereinafter referred to as TG), a memory 7, a synchronization signal generation unit 8, a memory control unit 9, and image processing. It comprises a unit 10, a system control unit 11, etc., and is connected via a bus with a data transfer unit 12 and a PC equipped with a computer 13 (operating according to the program 14).

  The image pickup device 3 projects an observation image of a specimen (test object) (not shown) of the microscope 1 onto the image pickup device 3 via an optical path (broken arrow in FIG. 1), and outputs the electric signal from the image pickup device 3. The For example, the image pickup device 3 is a solid-state image pickup device having a vertical overflow drain structure.

The preprocessing unit 4 converts the output signal from the image sensor 3 into an analog image signal.
The A / D converter 5 converts the analog image signal output from the preprocessing unit 4 into a digital image signal.

  The timing generation unit 6 is a pulse generator that drives the imaging device 3, the preprocessing unit 4, and the A / D converter 5. The TG 6 exposes the image sensor 3 in synchronization with the horizontal synchronization signal HD generated by the synchronization signal generator 8.

  Also, the TG 6 supplies a horizontal synchronization signal as a charge extraction pulse to the image sensor for the number of charge extraction pulses to extract the charge of the image sensor, and stops the charge accumulation of the image sensor after the exposure starts. A synchronous readout pulse is generated.

  Specifically, the TG 6 controls the exposure time by outputting a charge extraction pulse (hereinafter referred to as “SUB pulse”) supplied to the image sensor until the exposure start timing in the cycle of the vertical synchronization signal VD.

  Further, the TG 6 switches the drive pulse output to the image sensor 3 in accordance with the number of pixels read from the image sensor 3 (full pixel mode, two-pixel addition mode, four-pixel addition mode, partial readout for reading only a specific area). Further, the TG 6 supplies a conversion clock to the A / D converter 5.

  The synchronization signal generation unit 8 outputs the horizontal synchronization signal HD and the vertical synchronization signal VD to the TG 6, the memory control unit 9, and the system control unit 11. The synchronization signal generator 8 generates a vertical synchronization signal based on the VD time setting value and the horizontal synchronization signal output from the system controller 11.

  The period of the vertical synchronization signal VD varies depending on the number of pixels read from the image sensor 3. For example, the all-pixel mode is 67 (msec), the two-pixel addition mode is 34 (msec), the four-pixel addition mode is 19 (msec), and partial reading is determined by the reading area.

The memory control unit 9 writes the digital image signal from the A / D converter 5 into the memory 7 in synchronization with the horizontal synchronization signal HD and the vertical synchronization signal VD from the synchronization signal generation unit 8.
When the reading of the image signal is completed, the image signal is read via the data transfer unit 12 according to the program 14 operating on the computer 13.

At this time, the image processing unit 10 generates an image signal subjected to image processing such as noise reduction and gradation correction, and transfers the image signal to the computer 13 via the data transfer unit 12.
The system control unit 11 includes a CPU and a memory, and controls the A / D converter 5, the TG 6, and the memory control unit 9 in synchronization with the vertical synchronization signal VD.

  In addition, the system control unit 11 calculates how many periods the horizontal synchronization signal is within the imaging interval to obtain a VD time setting value. Further, in order to set the exposure time within the imaging interval, the number of charge extraction pulses is determined by calculating how many horizontal synchronization signals are present in the time from the imaging start to the exposure start timing. That is, the exposure time of the image sensor 3 is set by setting the number of cycles (number of SUB pulses) of the horizontal synchronization signal HD corresponding to the time obtained by subtracting the exposure time from the cycle of the vertical synchronization signal VD to TG6. Further, the system control unit 11 sets the cycle of the vertical synchronization signal VD by setting the number of cycles of the horizontal synchronization signal HD corresponding to the cycle of the vertical synchronization signal VD in the synchronization signal generation unit 8. The mode set by the system control unit 11 is reflected in the next vertical synchronization signal VD cycle.

The operation of the first embodiment will be described with reference to FIGS.
FIG. 2 is a flowchart of the VD extension process executed by the system control unit 11 according to the first embodiment of the present invention. Further, the VD extension process shown in FIG. 2 is a process executed in the period (a) of the time chart shown in FIG.

  In the time chart shown in FIG. 3, the vertical axis indicates signal waveforms (1) to (6), and the horizontal axis indicates the time axis. (1) The waveform of the vertical synchronizing signal VD is shown. (2) shows a SUB pulse (pulse for extracting charge from the image sensor). (3) A read pulse for reading an image signal from the image sensor 3 is shown. (4) A pixel accumulation amount of the image sensor 3 is shown. (5) An image signal (data) stored in the memory 7 is shown. (6) The image data generated by image processing of the image signal (data) is transferred to the computer 13. The horizontal axis is the time axis.

Hereinafter, the process of each step shown in FIG. 2 will be described.
In step S10, the rising or falling edge of the vertical synchronizing signal VD is detected as a trigger. 2 and 3, the rising edge of the vertical synchronizing signal VD is used as a trigger.

  In step S11 (exposure time calculation step), the system control unit 11 calculates the number of SUB pulses (number of charge extraction pulses) according to the following equation 1, and sets the calculated number of SUB pulses in TG6 (imaging interval). In order to set the exposure time, the number of horizontal sync signals in the time from the start of imaging to the exposure start timing is calculated to obtain the number of charge extraction pulses).

“SUB = (i−texp) / thd (Formula 1)
Here, i (sec) is the shooting interval, tex p (sec) is the exposure time, and thd is the period of the horizontal synchronization signal HD. The shooting interval i is set from an input unit (not shown) provided in the computer 13 necessary for the operator to start shooting repeatedly.

  In step S12 (VD time calculation step), the system control unit 11 calculates the number of pulses VD (VD time setting value) of the horizontal synchronization signal HD in the period of the vertical synchronization signal VD according to the following equation 2 to generate a synchronization signal. Is set in the unit 8 (the VD time setting value is obtained by calculating how many cycles the horizontal synchronizing signal is within the imaging interval).

VD = i / thd (Formula 2)

Here, there is a relationship of i> tref between the period (a) tref and the imaging interval i shown in FIG.

  The standard VD time tref (sec) is a cycle determined by the number of pixels read from the image sensor 3 and selects any one of the cycle determined by the reading area of the all pixel mode, the two-pixel addition mode, the four-pixel addition mode, and the partial reading. To do. As the above-described cycle, tref1 = 67 (msec) is selected for the all-pixel mode, tref2 = 34 (msec) for the two-pixel addition mode, and tref4 = 19 (msec) for the four-pixel addition mode.

The content set in the period (a) is reflected in the processing after the period (b).
Next, a vertical synchronizing signal is generated based on the VD time setting value and the horizontal synchronizing signal, and the horizontal synchronizing signal is supplied to the image sensor as the charge extracting pulse by the number of charge extracting pulses to extract the charge of the imaging element. Then, in order to stop the charge accumulation of the image sensor after the exposure is started, a readout pulse synchronized with the vertical synchronization signal is generated (timing control step).

The operation of each VD will be described below with reference to the timing chart of FIG.
In the period (b) of FIG. 3, the synchronization signal generator 8 changes to the imaging interval i (sec). The TG 6 outputs the SUB pulse only for the time obtained by subtracting the exposure time from the imaging interval i (VD cycle). Therefore, the image sensor 3 is exposed for a period of texp (sec). In FIG. 3, the image data “A” shown on the vertical axis (4) is taken in the period (b). In the period (c), the image data “B” is photographed, and after that, the image data “C” and the like are photographed continuously after the period (c).

  In the period (c), the image sensor 3 receives a read pulse from the TG 6 and starts outputting an image signal. The memory control unit 9 reads out the image signal converted into the digital image signal via the pre-processing unit 4 and the A / D converter 5 and stores it in the memory 7. At this time, since there is a relationship of imaging interval i> standard VD time tref, it is guaranteed that reading of the desired number of pixels is completed within the period of the vertical synchronization signal VD. In FIG. 3, the image data “A” in the period (c) indicated by the vertical axis (5) is read out. Subsequently, the image data “B” shown after the period (c) is read, and the image data “C” and the like are read continuously thereafter.

  When the reading of the image signal is completed, the program 14 operating on the computer 13 reads the image signal via the data transfer unit 12. At this time, the image processing unit 10 performs image processing such as noise reduction and gradation correction on the digital image signal stored in the memory 7 and transfers the digital image signal to the computer 13 via the data transfer unit 12. In the period (c), the processing executed in the period (b) is also executed in parallel. The image data “A” in the period (c) indicated by the vertical axis (6) in FIG. The image data “B” is read after the period (c), and the image data after the image data “C” is continuously read after the period (c).

  As described above, by continuing the operations shown in the periods (b) and (c) after the period (c), the microscope imaging apparatus does not require additional hardware or special hardware processing, and can be performed at an arbitrary imaging interval. A specimen image can be acquired with high accuracy.

(Example 2)
In the first embodiment, the configuration in which the vertical synchronization signal VD cycle is set to the shooting interval i is shown. However, in the second embodiment, one or more vertical synchronization signal VD cycles having different times are inserted in the shooting interval i. explain.

Period of the vertical synchronizing signal until the exposure time from the shooting start in the photographing interval is calculated what period is to determine the imaging interval divided value. The VD time setting value is set so that the synchronization signal generation unit 8 and the TG 6 supply the charge extraction pulse to the image sensor until the number of periods of the vertical synchronization signal is detected after the start of imaging and becomes the same value as the imaging interval division value. Sets the number of charge extraction pulses.

After the start of imaging, the number of periods of the vertical synchronization signal is detected and the synchronization signal generation unit 8 and the TG 6 supply the charge extraction pulse to the image sensor until the exposure start timing after the same value as the imaging interval division value is reached. Set the VD time setting value and the number of charge extraction pulses.

The operation of the second embodiment will be described below with reference to FIG.
FIG. 4 is a flowchart of the system control unit 11 in the second embodiment. The process of each step will be described below.

In step S201, the operator sets the shooting interval i by the computer 13 according to the program 14, and starts repeated shooting.
The system control unit 11 divides the imaging interval i (sec) into n standard VD times tref and one extended VD time having a length e. In Expression 3 below, n ( shooting interval division value) is an integer greater than or equal to 0, e is tref ≦ e ≦ tref × 2, and floor (X) in Expression 4 is the largest integer equal to or less than X. This is the function to find.

n = floor (i / tref) -1 (Formula 3)

e = i-tref × n (sec) (Formula 4)

In step S202, the system control unit 11 initializes the count value k of the VD counter that counts with the rising or falling edge of the vertical synchronization signal VD as a trigger to zero.

  In step S203, the determination value n set in advance and the count value k of the VD counter are compared. If k <n, the process proceeds to step S204. Otherwise, the process proceeds to step S206.

In step S204, parameters necessary for setting a VD insertion process to be described later are calculated by an arithmetic process.
In step S205, the system control unit 11 executes VD insertion processing when k <n, increments the counter value k (k ← k + 1), and proceeds to step S203.

In step S206, the system control unit 11 executes VD exposure processing described later when k ≧ n.
In step S207, it is determined whether shooting has been completed. The system control unit 11 monitors whether or not the repeated shooting has been completed a predetermined number of times, and repeats the processing from S201 to S206 until the predetermined number of shootings are completed.

The VD insertion process and the VD exposure process (S204) will be described below with reference to FIGS.
Steps S208 to S210 shown in FIG. 4 show the VD insertion process shown in step S204. The timing chart shown in FIG. 5 is an example when n = 2.

  In the time chart shown in FIG. 5, the vertical axis indicates the signal waveforms (1) to (6), and the horizontal axis indicates the time axis. (1) A vertical synchronizing signal VD waveform is shown. (2) shows the waveform of the SUB pulse (pulse for extracting charge from the image sensor). (3) A read pulse for reading an image signal from the image sensor 3 is shown. (4) A pixel accumulation amount of the image sensor 3 is shown. (5) An image signal (data) stored in the memory 7 is shown. (6) The image signal (data) generated by image processing of the image signal is transferred to the computer 13.

In step S208 in FIG. 4, the rising edge of the vertical synchronizing signal VD is detected as a trigger. The trigger of the vertical synchronizing signal VD may be rising or falling.
In this example, the system control unit 11 executes VD insertion processing in synchronization with the rising edge of the vertical synchronization signal VD indicated by the vertical axis (1) in the periods (d) and (e) shown in FIG.

  In step S209, the system control unit 11 calculates the number of horizontal synchronization signals HD time in the standard VD time tref according to the following formula 5, calculates the number of SUB pulses (number of charge extraction pulses), and stores the value in TG6. The calculated number of SUB pulses is set.

SUB = tref / thd (Formula 5)

In step S210, the system control unit 11 calculates VD (VD time set value) indicating the number of horizontal synchronization signal HD periods in the vertical axis (1) standard VD time tref according to the following equation (6). Set in the generation unit 8.

VD = tref / thd (Formula 6)

Here, thd (sec) is the horizontal synchronization signal HD time, and standard VD time tref (sec) is a cycle determined by the number of pixels read from the image sensor. For example, the total pixel mode is trefl = 67 (msec), the two-pixel addition mode is tref2 = 34 (msec), and the four-pixel addition mode is tref4 = 19 (msec), which is one of the periods determined by the readout area for partial readout. .

Next, the operation of the VD exposure process (S206) will be described.
In step S211, the system control unit 11 executes VD exposure processing in synchronization with the rising or falling edge of the vertical synchronization signal VD in the VD cycle (f).

The calculation method in the VD exposure process is shown below.
In step S212, the system control unit 11 calculates the number of SUB pulses (SUB: the number of charge extraction pulses) output in synchronization with the horizontal synchronization signal HD according to the following equation 7, and calculates the SUB pulse calculated in TG6. Set the number of.

SUB = (e-text) / thd (Formula 7)

In step S <b> 213, the system control unit 11 calculates VD indicating how many horizontal synchronization signal HD periods are in the VD extension time according to the following equation 8 and sets the VD in the synchronization signal generation unit 8.

VD = e / thd (Formula 8)

Here, e (sec) is the VD extension time calculated in S201, tex (sec) is the exposure time, and thd (sec) is the horizontal synchronization signal HD time.

  In the periods (d) and (e) of the vertical synchronizing signal VD in (1) of FIG. 5, the synchronizing signal generator 8 changes the VD cycle to tref (sec) (standard VD cycle). The TG 6 is not exposed because the SUB pulse is supplied to the image sensor 3 by the number of SUBs calculated in Expression 7 for each time of the horizontal synchronization signal HD during the period of the vertical synchronization signal VD of (2) in FIG.

  In (1) the period (f) of the vertical synchronization signal VD in FIG. 5, the synchronization signal generation unit 8 changes the vertical synchronization signal VD period to e (sec). The TG 6 outputs a SUB pulse only for a time e-text (sec) obtained by subtracting the exposure time from the vertical synchronization signal VD cycle calculated by the equation (8). Therefore, as shown in (4) of FIG. 5, the image sensor 3 is exposed for a period of tex (sec), and images the image data “A” and “B”.

  (1) In (g) of the vertical synchronization signal VD cycle, the image sensor 3 receives the readout pulse shown in (3) of FIG. 5 and starts outputting the image signal. As shown in (5) of FIG. 5, the memory control unit 9 receives the image signals (image data “A” and “B”) converted into digital image signals via the preprocessing unit 4 and the A / D converter 5. ) And stored in the memory 7. Reading of the image signal is completed. Then, as shown in (6) of FIG. 5, the program 14 operating on the computer 13 reads the image signal via the data transfer unit 12 (image data “A” and “B”). At this time, the image processing unit 10 performs image processing such as noise reduction and gradation correction on the digital image signal stored in the memory 7 and transfers the digital image signal to the computer 13 via the data transfer unit 12.

  In the image pickup apparatus described in the first embodiment, a long-time hardware counter is necessary for the synchronization signal generation unit, and the image pickup devices 3 and TG6 must correspond to a long-time vertical synchronization signal VD cycle. However, by doing as described above, a long-time hardware counter is not provided in order to cope with the period of the long-time vertical synchronization signal VD, and the image sensor 3 and TG 6 are not associated with the long-time VD period. A specimen image can be obtained with high accuracy at a desired imaging interval.

(Example 3)
The configuration of the third embodiment of the present invention will be described below with reference to FIG.
The period of the vertical synchronization signal is set to a period determined by the number of pixels read from the image sensor.

  In sync with the shooting interval, set the shooting interval to the still image shooting mode that detects the still image shooting instruction signal from the still image shooting instruction section and shoots the vertical sync signal. Switch the self-running mode to repeat shooting.

  In the still image shooting mode, when the still image shooting instruction signal is detected, the VD time setting value and the number of charge extraction pulses are set so that the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor until the exposure start timing. Set.

The VD time setting value and the number of charge extraction pulses are set so that the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor from the exposure completion to the imaging completion timing in the imaging interval.

  The still image shooting instruction unit (which generates a still image shooting instruction signal according to the installed program 14 on a PC having a computer 13 or the like) includes a software cycle timer that periodically generates an event. Periodically instruct still image shooting.

  The system control unit 11 sets the period of the vertical synchronization signal VD generated by the synchronization signal generation unit 8 to a period determined by the number of pixels read from the image sensor 3, and synchronizes with a still image shooting mode in which shooting is performed in response to a still image shooting instruction. It has a self-running mode in which the vertical synchronization signal VD cycle generated by the signal generator 8 is set to the shooting interval i, and shooting is repeated according to the vertical synchronization signal VD cycle.

  Hereinafter, the operation of the third embodiment of the present invention will be described with reference to FIG. FIG. 6 is an operation flowchart of the program 14 in the still image shooting mode. The operation of each step will be described below.

The operator repeats shooting by setting the shooting interval i (sec) in the program 14.
In step S31, the operator sets an arbitrary shooting interval i (sec), the still image shooting minimum interval is T (sec), and when i> T, the still image shooting mode is selected.

In step S32, the period of the software cycle timer that periodically generates an event that the program 14 operating on the computer 13 has is set to i (sec).
In step S33, the computer 13 (program 14) waits for the software cycle timer event.

  In step S34, when the event occurs, the computer 13 (program 14) instructs the system control unit 11 to shoot a still image. As described above, the system control unit 11 receives the still image shooting instruction and repeats the still image shooting.

  In step S35, when i ≦ T, the program 14 selects the free-running mode. The computer 13 (program 14) repeats the processing of the preset number of photographing steps S32 to S34 and completes photographing when the number of photographing is reached.

  Next, in step S36, the self-running mode is continued until the repeated shooting is completed. In the self-running mode, the system control unit 11 performs repeated shooting by setting the VD cycle to the shooting cycle i (sec) as shown in the first embodiment.

  The self-running mode is set in the system control unit 11 from the computer 13 (program 14). For example, tref1 = 67 (msec) for the all-pixel mode is set as the cycle, tref2 = 34 (msec) for the two-pixel addition mode, and tref4 = 19 (msec) for the four-pixel addition mode. Then, shooting is performed in the self-running mode.

  In step S37, similarly to S35, the computer 13 (program 14) repeats the processing of the preset number of photographing steps S32 to S34, and the photographing is completed when the number of photographing is reached.

FIG. 7 is a flowchart of the system control unit 11 in the still image shooting mode (still image processing). The operation of each step will be described below.
In step S40, it is determined whether there is a still image shooting instruction from the computer 13 via the bus. If there is no still image shooting instruction, the process loops through S40 and waits until a still image shooting instruction signal is detected. If an instruction is detected, the process proceeds to step S41.

In step S41, a VD exposure process described later is performed.
In step S42, a VD exposure stop process described later is performed.
As described above, when receiving a still image start instruction from the computer 13 (program 14), the system control unit 11 executes VD exposure processing and VD exposure stop processing.

The calculation method in the VD exposure process (S41) is shown below.
In step S43, in the period (h) shown in (1) vertical synchronization signal VD cycle shown in FIG. 8, the system control unit 11 executes VD exposure processing in synchronization with the rise of VD.

In step S44, the system control unit 11 calculates the number of SUB pulses (the number of charge extraction pulses) according to the following formula 9, and sets the calculated number of SUB pulses in TG6.

SUB = (tref−texp) / thd (Formula 9)

In step S <b> 45, the system control unit 11 calculates VD (VD time setting value) indicating how many horizontal synchronization signal HD periods are in the standard VD time according to the following equation 10 and sets the calculated value in the synchronization signal generation unit 8.

VD = tref / thd (Formula 10)

Here, tref (sec) is the VD time, texp (sec) indicates the exposure time, and thd (sec) is the horizontal synchronization signal HD time.

The calculation method in the VD exposure stop process (S42) is shown below.
In step S46, in (1) vertical synchronization signal VD cycle (i) shown in FIG. 8, the system control unit 11 executes VD exposure stop processing in synchronization with the rise of VD.

In step S47, the system control unit 11 calculates an exposure time SUB in accordance with the following equation and sets it to TG6.

SUB = tref / thd (Formula 11)

In step S <b> 48, the system control unit 11 calculates the standard VD time VD according to the following formula 12 and sets it in the synchronization signal generation unit 8.

VD = tref / thd (book) (Formula 12)

Here, tref (sec) represents the VD time, texp (sec) represents the exposure time, and HD time thd (sec). The standard VD time tref (sec) is a period determined by the number of pixels read from the image sensor. For example, the total pixel mode is tref1 = 67 (msec), the two-pixel addition mode is tref2 = 34 (msec), and the four-pixel addition is performed. The mode is tref4 = 19 (msec) and takes one of the periods determined by the read area for partial reading.

The operation of the third embodiment will be described below using the timing chart of FIG.
In the time chart shown in FIG. 8, the vertical axis indicates the signal waveforms (1) to (6), and the horizontal axis indicates the time axis. (1) A vertical synchronizing signal VD waveform is shown. (2) shows the waveform of the SUB pulse (pulse for extracting charge from the image sensor). (3) A read pulse for reading an image signal from the image sensor 3 is shown. (4) A pixel accumulation amount of the image sensor 3 is shown. (5) An image signal (data) stored in the memory 7 is shown. (6) The image signal (data) generated by image processing of the image signal is transferred to the computer 13.

In the period (h) shown in (1) vertical synchronization signal VD cycle shown in FIG. 8, as described above, the system control unit 11 executes VD exposure processing in synchronization with the rise of VD.
In the period (i) of the vertical synchronizing signal VD cycle in FIG. 8, the vertical synchronizing signal VD cycle generated by the synchronizing signal generator 8 is the standard VD time. The TG 6 outputs the SUB pulse only for the time obtained by subtracting the exposure time from the vertical synchronization signal VD cycle. Therefore, the image sensor 3 is exposed to tex (sec).

  In the period (j) of the vertical synchronization signal VD cycle in FIG. 8, the image sensor 3 receives the readout pulse (3) and starts outputting the image signal. (4) The memory control unit 9 reads the image signal converted into the digital image signal via the pre-processing unit 4 and the A / D converter 5 and stores it in the memory 7. When the reading of the image signal is completed, (5) the program 14 operating on the computer 13 reads the image signal via the data transfer unit 12. At this time, the image processing unit 10 performs image processing such as noise reduction and gradation correction on the digital image signal stored in the memory 7 and (6) transfers the digital image signal to the computer 13 via the data transfer unit 12.

Further, the vertical synchronization signal VD cycle generated by the synchronization signal generator 8 is a standard VD time. Since the TG 6 continues to generate the SUB pulse during the VD period, the image sensor 3 is not exposed.
As described above, by selecting the still image shooting mode when the shooting interval i> the still image shooting minimum interval T, a long-time hardware counter is provided to cope with the long-time VD cycle, or the image sensor 3 and the TG 6 are installed. A sample image can be obtained at a desired photographing interval without corresponding to a long VD cycle. By setting the still image shooting minimum interval T to be sufficiently long with respect to the transmission of the still image shooting instruction and the VD cycle, a sample image can be obtained with a certain degree of accuracy with respect to the shooting interval i. In addition, when the shooting interval i ≦ the still image shooting minimum interval T, by selecting the self-running mode, a sample image can be obtained with high accuracy at a desired shooting interval.

  The present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the gist of the present invention.

It is a figure which shows the block diagram which shows the structure of the imaging device for microscopes which is this invention. 3 is a flowchart showing the operation of the first embodiment. 3 is a time chart showing the operation of the first embodiment. 6 is a flowchart showing the operation of the second embodiment. 6 is a time chart showing the operation of the second embodiment. It is a flowchart which shows the operation | movement of the program in still image shooting mode. It is a flowchart which shows operation | movement of the system control part in still image shooting mode. 10 is a time chart illustrating an operation of the third embodiment.

Explanation of symbols

1 microscope,
2 Microscope imaging device,
3 image sensor,
4 Pre-processing section,
5 A / D converter,
6 Timing generator,
7 memory,
8 synchronization signal generator,
9 Memory control part,
10 Image processing unit,
11 System control unit,
12 Data transfer unit,
13 Calculator,
14 programs,

Claims (8)

A microscope imaging apparatus capable of time-lapse photography that repeatedly obtains a digital image at a desired photography interval,
Horizontal synchronizing signal to calculate the how many cycles within the shooting distance with obtaining the VD time setting value, the horizontal time from imaging start until the exposure start timing in order to set the exposure time in the imaging interval A system control unit for calculating how many periods of the synchronization signal and calculating the number of charge extraction pulses;
A synchronization signal generation unit that generates a vertical synchronization signal based on the VD time setting value output from the system control unit and the horizontal synchronization signal;
The horizontal synchronization signal is supplied to the image sensor as the charge extraction pulse for the number of charge extraction pulses to extract the charge of the image sensor, and the charge synchronization of the image sensor is stopped after the exposure is started. A timing generator for generating a synchronous readout pulse;
An imaging apparatus for a microscope, comprising: The system controller is
Wherein the period of the vertical synchronizing signal until the exposure time from the shooting start in the photographing interval is calculated how many cycles there obtains a photographing interval division value, by detecting the number of cycles of the vertical synchronization signal After the start photographing Set the VD time setting value and the number of charge extraction pulses so that the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor until the same value as the imaging interval division value,
After the start of imaging, the number of periods of the vertical synchronization signal is detected and after the value becomes equal to the imaging interval division value, until the exposure start timing, the synchronization signal generation unit and the timing generation unit apply the charge to the image sensor. Setting the VD time set value and the number of charge extraction pulses to supply extraction pulses;
The imaging apparatus for a microscope according to claim 1. The system controller is
A still image shooting mode in which the period of the vertical synchronization signal is set to a cycle determined by the number of pixels read from the image sensor, and shooting is performed when a still image shooting instruction signal is detected from the still image shooting instruction unit in synchronization with the shooting interval. When,
A self-running mode in which the period of the vertical synchronization signal is set to the imaging interval, and imaging is repeated according to the period of the vertical synchronization signal;
The imaging apparatus for a microscope according to claim 1, wherein the still image shooting mode and the self-running mode are switched according to the shooting interval. In the still image shooting mode,
When the still image shooting instruction signal is detected, the VD time setting value and the number of charge extraction pulses are set so that the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor until exposure start timing. Set
The VD time setting value and the number of charge extraction pulses are set so that the synchronization signal generation unit and the timing generation unit supply the charge extraction pulse to the image sensor from the exposure completion to the imaging completion timing in the imaging interval. The imaging apparatus for a microscope according to claim 3. An imaging method for a microscope capable of time-lapse photography that repeatedly obtains a digital image at a desired photography interval,
And VD time calculating step of obtaining a VD time setting value horizontal synchronizing signal to calculate the how many cycles within the imaging interval,
An exposure time calculating step for calculating the number of charge extraction pulses by calculating how many periods of the horizontal synchronization signal in the time from the start of shooting to the exposure start timing in order to set the exposure time within the shooting interval;
A vertical synchronization signal is generated based on the VD time setting value and the horizontal synchronization signal, and the horizontal synchronization signal is supplied to the image sensor as the charge extraction pulse by the number of charge extraction pulses to extract the charge of the image sensor. A timing control step of generating a readout pulse synchronized with the vertical synchronization signal in order to stop the charge accumulation of the image sensor after the start of exposure;
The imaging method for microscopes characterized by having. The timing control step includes:
Wherein the period of the vertical synchronizing signal until the exposure time from the shooting start in the photographing interval is calculated how many cycles there obtains a photographing interval division value, by detecting the number of cycles of the vertical synchronization signal After the start photographing Set the VD time setting value and the number of charge extraction pulses so as to supply the charge extraction pulse to the image sensor until the same value as the imaging interval division value,
The VD time setting is set so that the charge extraction pulse is supplied to the image sensor until the exposure start timing after the number of periods of the vertical synchronization signal is detected after the start of imaging and becomes the same value as the imaging interval division value. Set the value and the number of charge extraction pulses,
The imaging method for a microscope according to claim 5. The timing control step includes:
A still image shooting mode in which the period of the vertical synchronization signal is set to a cycle determined by the number of pixels read from the image sensor, and shooting is performed when a still image shooting instruction signal is detected from the still image shooting instruction unit in synchronization with the shooting interval. When,
A self-running mode in which the period of the vertical synchronization signal is set to the imaging interval, and imaging is repeated according to the period of the vertical synchronization signal;
The imaging method for a microscope according to claim 5 or 6, wherein the still image shooting mode and the self-running mode are switched according to the shooting interval. In the still image shooting mode,
When the still image shooting instruction signal is detected, the VD time setting value and the number of charge extraction pulses are set so that the charge extraction pulse is supplied to the image sensor until the exposure start timing.
8. The VD time setting value and the number of charge extraction pulses are set so as to supply the charge extraction pulse to the image sensor from the completion of exposure to the imaging completion timing in the imaging interval. Imaging method for microscope.

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