Image acquisition device and imaging device

Abstract

Image acquisition device for performing a signal readout by a rolling readout of each of a plurality of pixel rows to capture an image of an object illuminated by a scanning illumination light, comprising: a light receiving section in which the multitude of pixel rows are arranged; an image acquisition control section for controlling a signal readout of the light reception section based on a drive clock; and an external signal receiving section, coupled with the image acquisition control section and for receiving an external signal, wherein the external signal receiving section is coupled to a processing unit that generates the external signal, wherein the external signal comprises data specifying an interval of a start time of a signal readout between adjacent pixel rows, wherein the interval of a start time of a signal readout between adjacent pixel rows is calculated by the processing unit for synchronization with a sampling of the object with the illumination light, and where the start time of a signal readout of each pixel row is controlled based on the external signal.

Description

Technical field

[0001] The present invention relates to an image acquisition system and an image recording device for capturing an image of a viewing object. background

[0002] Recently, CMOS (complementary metal-oxide-semiconductor) cameras have been used to observe light from an object. CMOS cameras are generally more advantageous than CCD (charge-coupled device) cameras in terms of high readout speed, the ability to easily perform partial readouts, etc.

[0003] The non-patent literature 1 below and patent literature 1 below disclose the use of a CMOS sensor as an image acquisition element in a light sheet fluorescence microscope system (light sheet microscope system). In this microscope system, an observation object is acquired while the observation object is scanned with an excitation beam, and this scanning with the excitation beam is synchronized with the rolling shutter operation of the CMOS sensor. List of citations, patent literature

[0004] Patent literature 1: International publication WO 2011 / 120 629 A1

[0005] US 2013 / 0 021 474 A1 shows an image acquisition device with rolling readout and illumination synchronized to the readout.

[0006] EP 2 527 901 A2 also describes an image recording device with rolling readout and a lighting system that is synchronized to the readout. Non-patented literature

[0007] Non-patent literature 1: Eugen Baumgart and Ulrich Kubitscheck, “Scanned light sheet microscopy with confocal slit detection”, OPTICS EXPRESS, Volume 20, No. 19, pages 21805-21814, 3, September 3, 2012 Invention Summary Technical Problem

[0008] However, with the aforementioned conventional microscope system, it is difficult to allow a degree of freedom for the scanning speed of the excitation light because the scanning with the excitation beam must be synchronized with the roller shutter operation of the CMOS sensor. As a result, under a variety of conditions and for different objects, the conventional microscope system tends not to allow flexible observation.

[0009] Therefore, the present invention has been made with this problem in mind, and it is an object of the present invention to provide an image acquisition system and an image recording device that enable flexible observation with a high degree of freedom given a scanning speed of illumination light on the object being observed. Problem solving

[0010] To solve the above problem, an image acquisition system according to one aspect of the present invention is an image acquisition system for scanning an object with illumination light to capture an image of the object, comprising a light source for emitting the illumination light, a light scanning unit for receiving the illumination light from the light source and for scanning the object with the illumination light, a light scanning control unit for controlling the light scanning unit, an optical system for guiding light from the object, an image acquisition device comprising a light receiving section in which a plurality of pixel rows configured to receive the light guided by the optical system are arranged, and an image acquisition control section configured to control a signal-reading light receiving section.and for performing signal readouts by rolling readout of each of the plurality of pixel rows from the light receiving section, and a computing unit for calculating an interval of signal readout between adjacent pixel rows, based on a movement speed of an illuminated area on the light receiving section when scanned by the light scanning unit, wherein the image acquisition control section controls the signal readout of each pixel row based on the interval of the signal readout so calculated.

[0011] In the image acquisition system described above, the object is scanned by the light source using the illumination light emitted from the light source. The light generated by the object in response is then guided through the optical system, where it is captured by the image-taking device. This device performs the signal readout via the rolling shutter. During this process, the signal readout interval between adjacent pixel rows in the light-receiving section is calculated based on the speed of movement of the illuminated region within the light-receiving section of the image-taking device. The signal readout of each pixel row is then controlled based on this calculation.This gives the scanning speed of the illumination light at the object a degree of freedom, thereby enabling flexible observation of the object, and reduces the influence of background noise such as scattered light in the overall image into a light scanning area of ​​the object, thus enabling an improvement in spatial resolution.

[0012] As another solution, an image acquisition device according to another aspect of the present invention is an image acquisition device which performs signal readout by rolling readout of each of a plurality of pixel rows containing a light receiving section in which the plurality of pixel rows are arranged, and an image acquisition control section for controlling the signal readout of the light receiving section, wherein the image acquisition control section is configured to control the signal readout based on a drive clock, and to variably adjust the interval of the signal readout between adjacent pixel rows.

[0013] In the image acquisition device as described above, the signal readout interval between adjacent pixel rows in the light reception section is varied based on the drive clock. This gives a degree of freedom to the signal readout difference of each pixel row in an image signal of the observed object, thus enabling flexible viewing of the object. Advantageous invention effect

[0014] The present invention has enabled flexible viewing with a higher degree of freedom, which is given to the scanning speed of the illumination light at the object being viewed. Brief description of the drawings Fig. Figure 1 is a top view showing a schematic configuration of an image acquisition system 1 according to a preferred embodiment of the present invention. Fig. Figure 2 is a side view showing a schematic configuration of the image acquisition system 1 in Fig. 1 shows. Fig. Figure 3 is a drawing showing the relationships between the sampling states of the illumination light on a sample S and an illuminated region with a fluorescence image on an image acquisition element 19a in the image acquisition system 1 in Fig. 1 shows. Fig. Figure 4 is a drawing showing the scanning states of an illuminated region R1 on a light-receiving surface 19c of the image-acquiring device 19 in Fig. 1 and timings of exposure and signal readout in each pixel row 19d of the light receiving surface 19c, controlled according to the sampling states, shows. Fig. Figure 5 is a timing diagram showing a relationship between exposure periods and signal readout periods for the corresponding pixel row 19d in the image acquisition device 19. Fig. 1 are set. Fig. Figure 6 is a drawing which shows the illuminated region R1 on the light-receiving surface 19c of the image-taking device 19 in Fig. 1 and an exposure region R2 of the light receiving surface 19c, adjusted accordingly, by an image acquisition control section 19b. Fig. Figure 7 is a timing diagram showing the exposure periods set for the corresponding pixel rows 19d on the light-receiving surface 19c when the number of rows of the exposure region R2 is passed through the image acquisition control section 19b in Fig. 1 is controlled. Fig. Figure 8 is a timing diagram showing the exposure periods set for the corresponding pixel row 19d on the light-receiving surface 19c when the number of rows of the exposure region R2 is passed through the image acquisition control section 19b in Fig. 1 is controlled. Fig. Figure 9 is a timing diagram showing the exposure periods set for the corresponding pixel row 19d on the light-receiving surface 19c when the number of rows of the exposure region R2 is passed through the image acquisition control section 19b in Fig. 1 is controlled. Fig. Figure 10 are timing diagrams showing the relationship between exposure periods and signal readout periods set for the respective pixel row 19d in the image acquisition device 19 in a modification example of the present invention. Fig. Figure 11 are timing diagrams showing a relationship between exposure periods and signal readout periods set for each pixel row 19d in the image acquisition device 19 in another modification example of the present invention. Fig. Figure 12 are timing diagrams showing a relationship between exposure periods and signal readout periods set for each pixel row 19d in the image acquisition device 19 in another modification example of the present invention. Description of embodiments

[0015] Embodiments of the image acquisition system and the image recording device according to the present invention are described in detail below with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals without redundant description. It should be noted that each of the drawings is for illustrative purposes only, and parts subject to description are shown with special emphasis. For this reason, the dimensional relationships of elements in the drawings do not always coincide with the actual dimensions.

[0016] Fig. Figure 1 is a top view which schematically shows a configuration of the image acquisition system 1 according to an embodiment of the present invention, and Fig. 2 is a side view of the in Fig. The image acquisition system 1 of the present embodiment is a device for applying illumination light to a sample (object) S and acquiring a resulting fluorescence image (image). In the following description, an X-axis direction is defined as a direction along an optical axis of an illumination optics system of the illumination light applied to the sample S, a Y-axis direction as a direction along an optical axis of a detection optics system for fluorescence from the sample S perpendicular to the X-axis direction, and a Z-axis direction as a direction perpendicular to both the X-axis and the Y-axis directions.It should be noted that the image acquisition system 1 need not be limited to the configuration for acquiring the fluorescence image of sample S, but may have a configuration for acquiring a reflection image, a transmission image or a scattering image of sample S, or may be one of several different image acquisition systems such as microscope systems and flow cytometers of different configurations, such as brightfield microscope equipment, darkfield microscope equipment and reflection microscope equipment.

[0017] The image acquisition system 1 is configured to include: a light source 3 that emits illumination light of a predetermined wavelength to excite a fluorescent substance in the sample S; an optical scanner (light scanning unit) 7 that receives the illumination light from the light source 3 through a light guide 5; an optical scanner control unit (light scanning control unit) 9 that controls the optical scanner 7; a relay optical system (illumination optical system) 11 that guides the illumination light from the optical scanner 7; an objective lens (illumination optical system) 13 that converges the illumination light guided by the relay optical system 11 to the sample S; an objective lens (detection optical system) 15 that converges fluorescence from the sample S; and a relay optical system (detection optical system) 17 that guides the fluorescence from the objective lens 15.an image acquisition device 19, which captures a fluorescence image of the sample S guided by the relay optical system 17; and a processing unit 21, which is electrically connected to the image acquisition device 19 and the optical scanner control unit 9. The fluorescence image captured by the image acquisition device 19 is output by an output means (not shown), such as a display device coupled to the image acquisition system 1.

[0018] The light guide 5 can be composed of an optical fiber such as a single-mode fiber, or of another type of optical fiber or a lens. The optical scanner 7 scans with illumination light from the light guide 5 in at least one direction (e.g., in one direction along the XZ plane). Fig. 2) For example, the optical scanner 7 is a galvanometer scanner containing a galvanometer mirror. The optical scanner 7 scans with the illumination light, thereby enabling a region illuminated by the illumination light converged in the sample S via the relay optical system 11 and the objective lens 13 to be moved at least in one direction (e.g., in the Z-axis direction). Fig. 2) It is noted here that the illumination light applied to the sample S from the light source 3 via the light guide 5, the optical scanner 7, the relay optical system 11 and the objective lens 13 can be light of a point shape or light of a leaf shape, which propagates in one direction (for example in the Y-axis direction).

[0019] The image acquisition device 19 is a device comprising an image acquisition element 19a, which includes a light-receiving section in which a plurality of pixel rows are arranged, and an image acquisition control section 19b for controlling the exposure and signal readout of the image acquisition element 19a, and which can perform signal readout by rolling readout of each of the plurality of pixel rows from the non-receiving section. For example, the image acquisition device 19 is a camera device that includes a CMOS image sensor and enables exposure and signal readout by means of the so-called rolling shutter of the CMOS image sensor.The computing unit 21 coupled to this image acquisition device 19 consists of an information processing unit such as a personal computer and is configured to receive a signal at a scanning rate of the optical scanner 7 from the optical scanner control unit 9, to generate a signal to control the exposure and signal readout of each of the pixel rows of the image acquisition device 19, based on the received signal, and to send the generated signal to the image acquisition control section 19b of the image acquisition device 19 (the details of which will be described later).

[0020] Below, the relationships between the sampling states of the illumination light at sample S and the illuminated region with the fluorescence image in the image acquisition element 19a in the image acquisition system 1 are shown with reference to Fig. 3 described. Fig. Figures 3(a) to (d) are side views showing the sampling states of the illumination light on the sample S in time series and Fig. Figures 3(e) to (h) show focused states of the fluorescence image on the image acquisition element 19a corresponding to the sampling states of each. Fig. 3(a) to 3(d).

[0021] As in Fig. As shown in Figures 3(a) to (d), the illumination light applied to the sample S by scanning the optical scanner 7 moves (or is scanned) along one direction (the Z-axis direction). The image acquisition element 19a, as shown in Fig. Figures 3(e) to (h) show that the image acquisition element 19a is configured such that its light-receiving surface (light-receiving section) 19c is arranged perpendicular to the optical axis (the Y-axis direction) of the detection optics system, and such that the plurality of pixel rows 19d for capturing the fluorescence image focused on the light-receiving surface 19c are arranged along the Z-axis direction. By arranging and configuring the image acquisition element 19a as described above, the illuminated region R1, carrying the fluorescence image of the sample S focused on the light-receiving surface 19c, moves (or is scanned) along the arrangement direction (the Z-axis direction) of the plurality of pixel rows 19d according to the movement of a fluorescence-generated area in the sample S as scanned by the illumination light through the optical scanner 7. The area of ​​the illuminated region R1 can be set to a variety of ranges, and in the example of Fig. 3. The entire illumination optics system and detection optics system are adjusted so that the illuminated region R1 is set within an area to cover four lines of pixel rows 19d.

[0022] The following describes the operation of the exposure and signal readout of the image acquisition device 19 according to the scanning of the illuminated region of the sample S with reference to Fig. 4. Fig. Figures 4(a) to (e) are side views which chronologically show scanning states of the illuminated region R1 on the light-receiving surface 19c of the image-taking device 19 and Fig. Figures 4(f) to (j) are timing diagrams showing the timings of exposure and signal readout in each pixel row 19(d) of the light-receiving surface 19c, controlled according to the sampling states of the Fig. 4(a) to 4(e).

[0023] As in Fig. As shown in Figures 4(a) to (e), the optical scanner control unit 9 controls the scanning speed SP0 of the optical scanner 7 such that the movement speed of the light-receiving surface 19c becomes a predetermined speed SP1. This relationship between the scanning speed SP0 and the movement speed SP1 is determined by the configuration of the optical scanner 7, by a parameter defined by the configuration of the illumination optical system containing the relay optical system 11 and the objective lens 13, and by a parameter defined by the detection optical system containing the objective lens 15 and the relay optical system 17.

[0024] Based on the sampling states of the illumination region R1 as described above, the exposure and signal readout timings in each pixel row 19d are controlled by the image acquisition control section 19b. Specifically, the image acquisition control section 19b performs control such that a signal readout period for reading a charge signal is set for each pixel row 19d immediately after an exposure period, which is a period for exposure with the fluorescence image and accumulation of the charge signal. This period is repeated in a predetermined cycle, containing both the exposure period and the signal readout period. The lengths of the exposure period and signal readout period, as well as their start and end times, are set based on an internally generated drive clock.

[0025] More specifically, the image acquisition control section 19b generates a reset signal RST at a time synchronized with the drive clock when a certain row of pixels 19dn (n is any natural number) enters the illuminated region R1, in accordance with the scanning of the optical scanner 7, in order to dissipate charge in the row of pixels 19dn and initiate an exposure process ( Fig. 4(a) and (f)). The image acquisition control section 19b then counts the drive cycle to generate a reset signal RST to adjust the exposure period for the adjacent pixel row 19d(n+1) in the scanning direction after a predetermined interval ( Fig. 4(b) and (g)). In this way, exposures of all pixel rows 19d of the light-receiving surface 19c are started sequentially, with the interval of the predetermined period between pixel rows 19d adjacent in the scan direction.

[0026] Furthermore, the image acquisition control section 19b performs a control such that the drive clock is counted in order to generate a readout start signal S1 after a time point after continuation of the exposure period of the pixel row 19dn for a predetermined period T1n in order to start the readout of the load signal of the pixel row 19dn ( Fig. 4(c) and (h)). The charge signal accumulated in pixel row 19dn is converted into a voltage to be read out. Furthermore, the image acquisition control section 19b performs such control that the drive clock is counted in order to generate a readout end signal S2 at a time after the signal readout period of pixel row 19dn has resumed for a predetermined period T2n, in order to terminate the readout of the charge signal of pixel row 19dn ( Fig. 4(d) and (i)).

[0027] Similarly, the image acquisition control section 19b sets the signal readout period T2(n+1) for the pixel row 19d(n+1) adjacent to the pixel row 19dn. When reading the signal by rolling readout in the image acquisition device 19, the readout timings must be differentiated between the respective pixel rows 19d, and to equalize the exposure periods for the respective pixel rows 19d, the exposure start timings must be shifted row by row for the pixel rows. In the example of Fig. 4 The image acquisition control section 19b sets the generation time of the readout start signal S1 with a difference of a predetermined interval ΔT1 between adjacent pixel rows 19d, thereby shifting the start time of the signal readout by the predetermined interval ΔT1 between adjacent pixel rows 19d.

[0028] It is noted herein that the difference (interval) ΔT1 of the start time of the signal readout, set by the image acquisition control section 19b, is variably set by a control signal sent from the computing unit 21 to the image acquisition control section 19b. Specifically, the computing unit 21 acquires information about a scanning speed SP0 of the optical scanner 7 from the optical scanner control unit 9 and calculates the movement speed SP1 of the illuminated region R1 on the light-receiving surface 19c, based on the scanning speed SP0, a parameter defined by an increase in the size of the illumination optical system or the like, and a parameter defined by an increase in the size of the detection optical system or the like.Furthermore, the processing unit 21 calculates the interval of the exposure period start time in order to sequentially start the exposure of the pixel row 19d, which enters the illuminated region R1 synchronously with the movement of the illuminated region R1 on the light-receiving surface 19c, based on the calculated movement speed SP1. In connection with this, it determines an interval ΔT1' of the signal readout start time between adjacent pixel rows 19d from an interval of signal readout between adjacent pixel rows 19d. The processing unit 21 then sends the interval ΔT1' of the signal readout start time calculated in this way as an external signal to an external signal receiving section 19e of the image acquisition device 19. The received interval ΔT1' of the signal readout start time is sent as data to the image acquisition control section 19b.This allows the image acquisition control section 19b to control the signal readout of each pixel row, for example, the start time of the signal readout of each pixel row, based on the interval ΔT1' of the signal readout start time set by the processing unit 21. The image acquisition device 19 can include the processing unit 21. In this case, the external signal receiving section 19e of the image acquisition device 19 receives data such as the scanning speed SP0, the parameter defined by the magnification of the illumination optics system or the like, and the parameter defined by the magnification of the detection optics system or the like as external signals. The external signals need not be limited to these, as long as they are data or parameters for setting the interval ΔT1' of the signal readout start time.

[0029] The following describes the operation of the setting of the interval ΔT1 of the start time of the signal readout read by the image acquisition control section 19b, in more detail with reference to Fig. 5. Fig. Figure 5 is a timing diagram showing the relationships between exposure periods and signal readout periods set for each pixel row 19d in the image acquisition device 19.

[0030] Fig. Figure 5(a) is a timing diagram showing the relationship between exposure periods and signal readout periods for standard rolling readout. In standard rolling readout, the signal readout period T2 is set to a duration necessary for signal readout, and the interval ΔT1 of the signal readout start time is set to the signal readout period T2. Therefore, the image acquisition control section 19b counts the drive clock CLK, repeated in a predetermined cycle T0, by a count equivalent to the interval ΔT1 of the signal readout start time from the readout start signal S1 for the previous pixel row 19d, in order to generate the readout start signal S1 for the adjacent subsequent pixel row. In contrast, in Fig. 5(b) A variable delay period T3 after the signal readout period T2, equivalent to the time required for signal readout, is provided to adjust the interval ΔT1 of the signal readout start time to the set interval ΔT1' of the signal readout start time. Specifically calculated in Fig. 5(b) The image acquisition control section 19b determines the delay time T3 from the start interval ΔT1' of the signal readout start time and the signal readout period T2, and adjusts the drive clock such that the delay period T3 is provided at a time after the drive clock CLK one pulse before its arrival at the clock count equivalent to the signal readout period T2 in the drive clock CLK (or a time immediately before the generation of the readout start signal S1). At this time, the image acquisition control section 19b does not generate a drive clock in the delay period T3 and therefore counts the drive clock CLK by the same count as the drive clock CLK equivalent to ΔT1 in Fig. 5(a) to generate the readout start signal S1 for the next line of pixel row 19d. As a result, the interval of the signal readout start time between adjacent pixel rows 19d is set to the time ΔT1' = T2 + T3. Operating in this way, the image acquisition control section 19b can variably control the signal readout start time of each pixel row based on the interval ΔT1' of the signal readout start time calculated by the processing unit 21. It is noted that the timing of the provision of the delay period T3 need not be limited to the time immediately before the generation of the readout start signal S1, but can be provided within the signal readout period T2.

[0031] Furthermore, the image acquisition control section 19b is configured to be able to variably adjust the number of pixel rows in the exposure region on the light receiving surface 19c to be exposed simultaneously by adjusting the exposure periods for the corresponding pixel rows 19d. Fig. Figure 6 shows the illuminated region R1 on the light-receiving surface 19c of the image acquisition device 19 and the exposure region R2 on the light-receiving surface 19c, adjusted accordingly by the image acquisition control section 19b. Generally, from an optical point of view, it is difficult to make the fluorescence from the sample S incident on the light-receiving surface 19c in a slit shape. Therefore, the area of ​​the exposure region R2, which includes the simultaneously exposed pixel rows 19d (the number of lines), is adjusted by the image acquisition control section 19b, making it possible to record the fluorescence in a pseudo-slit state of incidence.

[0032] specifically show Fig. Figures 7 to 9 show the exposure periods set for the corresponding pixel row 19d on the light-receiving surface 19c when the number of rows in the exposure region R2 is controlled by the image acquisition control section 19b. In each of the drawings, (a) shows the exposure region R2 set on the light-receiving surface 19c, and (b) shows the exposure periods T1 and signal readout periods T2 of the corresponding pixel row 19d, set according to the exposure region R2 shown in (a). The exposure periods T1 and signal readout periods T2 set in the corresponding rows are adjusted such that the interval of the start time of each period between adjacent pixel rows 19d is synchronized with the movement of the illuminated region R2 on the light-receiving surface 19c, based on the calculation result of the computation unit 21.

[0033] If the exposure region R2 is set across four lines, as shown in Fig. As shown in Figure 7, the image acquisition control section 19b sets the length of the exposure periods T1 such that the number of pixel rows 19d whose exposure periods overlap T1 is four. Specifically, the calculation unit 21 acquires the information on the scanning speed SP0 of the optical scanner 7 from the optical scanner control unit 9 and calculates the length T1 of the exposure periods set for the corresponding pixel row 19d, based on the movement speed SP1 of the illuminated region R1 on the light-receiving surface 19c, which is calculated based on the scanning speed SP0 and the width W1 of the pixel row 19d. Fig. 6) in the scanning direction (rolling readout direction) of the light-receiving surface 19c, the desired number of pixel rows 19d in the exposure region R2 is set. Furthermore, the processing unit 21 sends the length T1 of the exposure periods calculated in this way as an external signal to the external signal receiving section 19e of the image acquisition device 19. The received external signal is sent to the image acquisition control section 19b. This allows the image acquisition control section 19b to variably adjust the length T1 of the exposure periods. For example, the image acquisition control section 19b changes a drive clock count that defines the length of the exposure periods in order to change the length T1 of the exposure periods. The processing unit 21 is configured to be able to variably adjust the number of pixel rows 19d in the exposure region R2 in order to determine the length T1 of the exposure periods.Since the exposure region R2 is set in this way using a plurality of lines, the sensitivity of the fluorescence image acquisition is improved.

[0034] Similarly, if the exposure region R2 is set over a line, as in Fig. As shown in Figure 8, the image acquisition control section 19b sets the length of the exposure periods T1 such that there is no overlap between the exposure periods T1 and the adjacent pixel row 19d, based on the calculation result of the calculation unit 21. If the exposure region R2 is set to a relatively small number of lines, for example one line, the spatial resolution of the image acquisition of the fluorescence image is improved in this way.

[0035] Furthermore, as in Fig. As shown in Figure 9, the exposure region R2 is set via a line, and the image acquisition control section 19b adjusts the length of the exposure periods T1 so that no overlap is placed between the exposure periods T1 of adjacent pixel rows 19d, based on the calculation result of the calculation unit 21. At this time, compared to Fig. 9. The movement speed SP1 of the illuminated region R1 is set lower, and for this reason, the lengths of the exposure periods T1 and the signal readout periods T2 are set relatively longer. Since the exposure region R2 is set to the relatively small number of lines in this way, the spatial resolution of the fluorescence image acquisition improves, and the sensitivity is improved because the exposure period of each pixel row is 19d longer than in the cases of Fig. 7 and Fig. 8 will be. On the other hand, the temporal resolution in the cases of Fig. 7 and Fig. 8 is superior because the sampling rate is higher than in Fig. 9 is.

[0036] Furthermore, it is also possible to set the number of pixels to be subjected to signal readout from the majority of pixels that make up the 19d pixel row and to define the set number of pixels as a parameter for calculating the exposure period T1. In this way, if it is unnecessary to read out the entire 19d pixel row, it becomes possible to read only the necessary pixels. Additionally, it becomes possible to set a short signal readout period T2, and a further degree of freedom can be given to setting the interval ΔT1 of the start time of the signal readout.

[0037] In the image acquisition system 1 described above, the sample S is scanned by the optical scanner 7 using the illumination light emitted from the light source 3, and the fluorescence generated in response from the sample S is image-captured by the image acquisition device 19 via the detection optics system. During this process, the interval of the signal readout start time between adjacent pixel rows 19d of the light-receiving surface 19c is calculated based on the movement speed of the illuminated region R1 on the light-receiving surface 19c of the image acquisition device 19 during scanning with the illumination light, and the signal readout start time of each pixel row 19d is controlled based on the calculation result.Since the aforementioned control system can optimize the signal readout timing in the image acquisition element accordingly, even with changes in the sampling rate of the illumination light, the sampling rate of the illumination light at sample S is given one degree of freedom, thus enabling flexible viewing of sample S. If the exposure of a necessary pixel row is performed only during the period of fluorescence application, the spatial resolution can be improved, while the influence of background noise, such as stray light, in the overall image within the light sampling range of sample S is reduced.

[0038] Here, the image acquisition device 19 is configured such that the signal readout start time is controlled based on the drive clock, and the signal readout start time interval is adjusted by providing the delay period in the drive clock. This allows the signal readout start time of each pixel row 19d to be easily and reliably set without being limited by an upper limit of a counter for counting the drive clock. It also allows the signal readout start time interval of each pixel row 19d to be finely adjusted. Furthermore, since the drive clock frequency is maintained, there is no need for a rolling readout timing optimization process by changing the frequency.

[0039] Since the number of lines in the exposure region R2 on the light-receiving surface 19c can be adjusted as needed by setting the exposure period of each pixel row 19c on the light-receiving surface 19c, it is possible to adequately adjust the spatial resolution, the temporal resolution and the sensitivity of the image acquisition depending on observation and measurement.

[0040] Additionally, it is possible to variably adjust the number of pixels to be subjected to signal readout from the plurality of pixels that make up each pixel row 19d. This allows for adjustment of the signal readout period T2 and makes it possible to give the setting of the interval ΔT1 of the start time of the signal readout another degree of freedom.

[0041] It is noted that the present invention is by no means limited to the embodiment mentioned above. For example, a different adjustment method may be used for adjusting the interval ΔT1 of the starting point of the signal readout by the image acquisition control section 19b.

[0042] Fig. Figure 10 are timing diagrams showing the relationship between exposure periods and signal readout periods set for the respective pixel rows 19d in the image acquisition device 19 in a modification example of the present invention. In the case shown in the same drawing, the image acquisition control section 19b sets the interval ΔT1 of the signal readout start time between adjacent pixel rows 19d by adjusting the drive clock counter, which defines the signal readout period T2 of each pixel row. Specifically, the image acquisition control section 19b calculates a clock count of the drive clock CLK equivalent to the interval ΔT1' of the signal readout start time, based on the interval ΔT1' of the signal readout start time calculated by the processing unit 21 and the frequency 1 / T0 of the drive clock CLK, and adjusts the drive clock count as a clock count corresponding to the signal readout period T2a.Therefore, the image acquisition control section 19b counts the drive clock CLK, repeated in the predetermined cycle T0, by a count equivalent to the interval ΔT1' of the signal readout start time from the readout start signal S1 for the previous pixel row 19d, in order to generate the readout start signal S1 for the adjacent subsequent pixel row. Through this operation, the image acquisition control section 19b can variably control the signal readout start time of each pixel row depending on the interval ΔT1 of the signal readout start time calculated by the processing unit 21. In this case, the signal readout start time of each pixel row 19d can be easily and reliably set. Even if the drive clock is applied at the time of completion of the signal readout of each pixel row, an idle readout is performed without affecting the signal readout processing.Furthermore, since the frequency of the drive cycle is maintained, there is no need for the optimization process of rolling readout timing by changing the frequency.

[0043] Furthermore, in Fig. Eleven timing diagrams showing the relationship between exposure periods and signal readout periods set for the respective pixel rows 19d in the image acquisition device 19, in another modification example of the present invention. In the case shown in the same drawing, the image acquisition control section 19b sets the start time of the signal readout of each pixel row 19d by adjusting the frequency of the drive clock that defines the signal readout period T2 of each pixel row. Specifically, the control section calculates the frequency 1 / T0a of the drive clock in order to change the frequency according to the signal readout period T2b, based on the interval ΔT1' of the signal readout start time calculated by the processing unit 21 and the clock count defining the signal readout period T2, and adjusts the frequency of the drive clock CLK to the calculated frequency 1 / T0a.Therefore, the image acquisition control section 19b counts the drive clock CLK repeated in the predetermined cycle T0a by a count equivalent to the interval ΔT1' of the signal readout start time from the readout start signal S1 for the preceding pixel row 19d, in order to generate the readout start signal S1 for the adjacent subsequent pixel row. Through this operation, the image acquisition control section 19b can variably control the signal readout start time of each pixel row depending on the interval ΔT1 of the signal readout start point calculated by the processing unit 21. In this case, the signal readout start time of each pixel row 19d can be easily and reliably set without being limited by the upper limit of the counter for counting the drive clock.

[0044] Fig. Figure 12 are timing diagrams showing the relationship between exposure periods and signal readout periods set for the respective pixel row 19d in the image acquisition device 19 in another modification example of the present invention. In the case shown in the same drawing, the image acquisition control section 19b sets the interval ΔT2 between the end time of the signal readout of the previous line of pixel row 19d and the start time of the signal readout of the subsequent line of the pixel row by adjusting a drive clock count that defines the interval ΔT2. Specifically, the control section calculates the interval ΔT2 based on the interval ΔT1' of the signal readout start time calculated by the processing unit 21, the signal readout period T2, and the frequency 1 / T0 of the drive clock CLK.In more detail, the image acquisition control section 19b first counts the drive clock CLK, repeated in the predetermined cycle T0, by means of a count equivalent to the signal readout period T2, starting from the readout start signal S1 for the previous pixel row 19d, in order to generate the readout end signal S2. Then, the control section counts the number of clock cycles equivalent to the interval ΔT2 from the readout end signal S2 to generate the readout start signal S1 for the subsequent, adjacent pixel row 19d. Since the image acquisition control section 19b counts the clock cycles equivalent to the period T2c, which results from adding the interval ΔT2 to the signal readout period T2, the start time of the signal readout for each pixel row can be variably controlled depending on the interval ΔT1 of the signal readout start time calculated by the processing unit 21.In this case, since the frequency of the drive clock is maintained, there is no need for the optimization process of rolling readout timing by changing the frequency.

[0045] The procedures for setting the interval of the start time of the signal readout, which are described in Fig. 5 and Fig. The parameters shown in sections 10 to 12 can be configured in optional combinations. Furthermore, any method can be configured depending on the interval ΔT1' of the start time of the signal readout from the parameters shown. Fig. 5 and Fig. The 10 to 12 shown setting methods can be selected.

[0046] The image acquisition control section 19b may include an integrated image sensor. In the foregoing embodiment, the signal readout start time interval was calculated (or set) and the image acquisition control section 19b controlled the signal readout start time for each pixel row; however, it is also possible, for example, to calculate (or set) a signal readout end time interval and control the signal readout end time for each pixel row.

[0047] It is noted herein that in the aforementioned image acquisition system, the image acquisition device is preferably configured such that the signal readout is controlled based on the drive clock, and such that the image acquisition control section adjusts the drive clock based on the calculated signal readout interval. Using this configuration, it is feasible to easily and reliably adjust the signal readout interval of each pixel row in the image acquisition device.

[0048] The image acquisition control section is also preferably configured to adjust the drive clock by providing the delay period. In this case, the signal readout interval of each pixel row in the image acquisition device can be finely adjusted.

[0049] Furthermore, the image acquisition control section is preferably configured to set the delay period before signal readout. This makes it possible to easily adjust the signal readout difference between pixel rows.

[0050] Furthermore, the image acquisition control section is preferably also configured to adjust the drive clock by changing the drive clock frequency. This makes it possible to easily adjust the signal readout interval of each pixel row.

[0051] The image acquisition device is preferably configured such that the signal readout is controlled based on the drive clock, and such that the image acquisition control section adjusts the count of the drive clock that defines the signal readout based on the calculated signal readout interval and the drive clock frequency. Using this configuration, the signal readout interval of each pixel row in the image acquisition device can be easily and reliably set.

[0052] Furthermore, the image acquisition control section is preferably configured to adjust the count of the drive clock, which defines the signal readout interval. This makes it easy to adjust the signal readout difference between pixel rows.

[0053] Furthermore, the image acquisition control section is also preferably configured to adjust the count of the drive clock, which defines the period of the signal readout. This makes it possible to easily adjust the difference in signal readout between pixel rows.

[0054] The processing unit is preferably configured to adjust the exposure period through the light-receiving section based on the movement speed of the illuminated region, the width of the pixel array, and the number of pixel arrays corresponding to the illuminated region. Using this configuration, the number of pixel arrays that can be exposed simultaneously can be set as required, thus making it possible to adequately adjust the spatial and temporal resolution.

[0055] Furthermore, it is also preferred to adjust the number of pixel rows variably according to the illuminated region. In this case, the spatial resolution can be freely adjusted.

[0056] Furthermore, the image acquisition control section is preferably also configured to variably adjust the number of pixels to be subjected to signal readout from the plurality of pixels that make up each pixel row. In this case, it is easy to set the signal readout period and it becomes feasible to provide another degree of freedom in setting the signal readout interval.

[0057] It is noted here that in the aforementioned image acquisition device, the signal readout interval between adjacent pixel rows is preferably set based on the speed of movement of the illuminated region on the light-receiving section. This makes it possible to reduce the influence of background noise, such as stray light, in the overall image within the light-scanning area of ​​the object and to improve the spatial resolution.

[0058] The image acquisition control section is preferably configured to adjust the drive clock based on the signal readout interval, which is calculated based on the movement speed of the illuminated region to the light receiving section. Using this configuration, it is feasible to easily and reliably adjust the signal readout interval of each pixel row in the image acquisition device.

[0059] The image acquisition control section is also preferably configured to adjust the drive clock by providing the delay period. In this case, it is possible to fine-tune the signal readout interval of each pixel row in the image acquisition device.

[0060] Furthermore, the image acquisition control section is preferably configured to set the delay period before readout. This makes it easy to adjust the signal readout difference between pixel rows.

[0061] Furthermore, the image acquisition control section is preferably configured to adjust the drive clock by changing the drive clock frequency. This makes it possible to easily adjust the signal readout interval of each pixel row.

[0062] The image acquisition control section is preferably configured to adjust the count of the signal-reading defining drive pulse based on the signal readout interval, which is calculated based on the movement speed of the illuminated region to the light-receiving section, and the frequency of the drive pulse. Using this configuration, it is feasible to easily and reliably adjust the signal readout interval of each pixel row in the image acquisition device.

[0063] Furthermore, the image acquisition control section is preferably configured to adjust the counting of the drive clock, which defines the signal readout interval. This makes it possible to easily adjust the signal readout difference between pixel rows.

[0064] Furthermore, the image acquisition control section is also preferably configured to adjust the drive clock count, which defines the signal readout period. This makes it easy to adjust the signal readout difference between pixel rows.

[0065] It is also preferred to adjust the exposure period by the light-receiving section based on the movement speed of the illuminated region, the width of the pixel row, and the number of pixel rows corresponding to the illuminated region. Using this configuration, the number of pixel rows that can be exposed simultaneously can be adjusted according to requirements, thus making it possible to adequately adjust the spatial and temporal resolution.

[0066] It is still preferable to adjust the number of pixel rows variably according to the illuminated region. In this case, it is possible to freely adjust the spatial resolution.

[0067] Furthermore, the image acquisition device is preferably configured to include an external signal reception section configured to receive the external signal and configured such that the signal readout interval between adjacent pixel rows is set based on the external signal. Using this configuration, it is possible to easily adjust the signal readout interval of each pixel row in the image signal of the object being viewed, thus enabling flexible viewing of the object.

[0068] The image acquisition control section is also preferably configured to variably adjust the number of pixels subjected to signal readout from a plurality of pixels that comprise each pixel row. In this case, it is easy to adjust the signal readout period, and it becomes feasible to provide an additional degree of freedom in setting the signal readout interval.

[0069] Further embodiments of the present invention are E1 to E24.

[0070] E1. Image acquisition system for scanning an object with illumination light to capture an image of the object, comprising: a light source for emitting the illumination light, a light scanning unit for receiving the illumination light from the light source and for scanning the object with the illumination light, a light scanning control unit for controlling the light scanning unit, an optical system for guiding light from the object, an image acquisition device comprising a light receiving section in which a plurality of pixel rows configured to receive the light guided by the optical system are arranged, and an image acquisition control section configured to control a signal-reading light receiving section, and for performing signal readouts by rolling readout of each of the plurality of pixel rows from the light receiving section.and a calculation unit for calculating an interval of signal readout between adjacent pixel rows, based on a movement speed of an illuminated area on the light receiving section when scanned by the light scanning unit, wherein the image acquisition control section controls the signal readout of each pixel row based on the interval of the signal readout so calculated.

[0071] E2. Image acquisition system according to embodiment E1, wherein the image acquisition device is configured such that the signal readout is controlled based on a drive clock, and wherein the image acquisition control section adjusts the drive clock based on the calculated interval of the signal readout.

[0072] E3. Image acquisition system according to embodiment E2, wherein the image acquisition control section adjusts the drive clock by providing a delay period.

[0073] E4. Image acquisition system according to embodiment E3, wherein the image acquisition control section sets the delayed period before signal readout.

[0074] E5. Image acquisition system according to embodiment E2, wherein the image acquisition control section adjusts the drive clock by changing a frequency of the drive clock.

[0075] E6. Image acquisition system according to embodiment E1, wherein the image acquisition device is configured such that the signal readout is controlled based on a drive clock, and wherein the image acquisition control section adjusts a count of the drive clock, which defines the signal readout, based on the calculated interval of the signal readout and a frequency of the drive clock.

[0076] E7. Image acquisition system according to embodiment E6, wherein the image acquisition control section adjusts a count of the drive cycle that defines the signal readout interval.

[0077] E8. Image acquisition system according to embodiment E7, wherein the image acquisition control section adjusts a count of the drive cycle that defines a period of signal readout.

[0078] E9. Image acquisition system according to one of embodiments E1 to E8, wherein the computing unit sets an exposure period through the light receiving section based on the speed of movement of the illuminated region, a width of the pixel row and a number of pixel rows corresponding to the illuminated region.

[0079] E10. Image acquisition system according to embodiment E9, wherein the number of pixel rows is variably set according to the illuminated region.

[0080] E11. Image acquisition system according to one of embodiments E1 to E10, wherein the image acquisition control section variably sets a number of pixels to be subjected to signal readout from a plurality of pixels forming each of the pixel rows.

[0081] E12. Image acquisition device performing signal readout by rolling the readout of each of a plurality of pixel rows, comprising: a light receiving section in which the plurality of pixel rows are arranged, and an image acquisition control section for controlling the signal readout of the light receiving section, wherein the image acquisition control section is configured to control the signal readout based on a drive clock, and to variably adjust an interval of signal readout between adjacent pixel rows.

[0082] E13. Image acquisition device according to embodiment E12, wherein the signal readout interval between adjacent pixel rows is set based on a movement speed of an illuminated region on the light receiving section.

[0083] E14. Image acquisition device according to embodiment E13, wherein the image acquisition control section adjusts the drive clock based on the signal readout interval calculated based on the movement speed of the illuminated region on the light receiving section.

[0084] E15. Image acquisition device according to embodiment E14, wherein the image acquisition control section adjusts the drive clock by providing a delay period.

[0085] E16. Image acquisition device according to embodiment E15, wherein the image acquisition control section sets the delay period before signal readout.

[0086] E17. Image acquisition device according to embodiment E14, wherein the image acquisition control section adjusts the drive clock by changing a frequency of the drive clock.

[0087] E18. Image acquisition device according to embodiment E13, wherein the image acquisition control section adjusts a count of the drive pulse defining the signal readout, based on the interval of the signal readout calculated based on the movement speed of the illuminated region to the light receiving section and a frequency of the drive pulse.

[0088] E19. Image acquisition device according to embodiment E18, wherein the image acquisition control section adjusts a count of the drive cycle which defines the interval of signal readout.

[0089] E20. Image acquisition device according to embodiment E18, wherein the image acquisition control section adjusts a count of the drive cycle which defines a period of signal readout.

[0090] E21. Image recording device according to one of embodiments E12 to E20, wherein an exposure period is set by the light receiving section based on a movement speed of an illuminated region on the light receiving section, a width of the pixel row and a number of pixel rows corresponding to the illuminated region.

[0091] E22. Image acquisition device according to embodiment E20, wherein the number of pixel rows is variably set according to the illuminated region.

[0092] E23. Image acquisition device according to one of embodiments E12 to E22, further comprising an external signal receiving section configured to receive an external signal, wherein the signal readout interval between adjacent pixel rows is set based on the external signal.

[0093] E24. Image acquisition device according to one of embodiments E12 to E23, wherein the image acquisition control section variably sets a number of pixels to be subjected to signal reading from a plurality of pixels forming each of the pixel rows. Industrial applicability

[0094] The present invention is applicable to use as an image acquisition system and the image recording device for capturing the image of the object being viewed, and has enabled flexible viewing with a higher degree of freedom, which is given to the scanning speed of the illumination light on the object being viewed. Reference symbol list

[0095] 1 Image acquisition system; 3 Light source; 7 Optical scanner (light scanning unit); 9 Optical scanner control unit (light scanning control unit); 15 Objective lens (detection optics system); 17 Relay optics system (detection optics system); 19 Image acquisition device, 19b Image acquisition control section, 19c Light receiving surface (light receiving section); 19d Pixel array; 19e External signal receiving section; 21 Computing unit; S Sample (object).

Claims

[1] Image acquisition device for performing a signal readout by rolling readout of each of a plurality of pixel rows to capture an image of an object illuminated by a scanning illumination light, comprising: a light receiving section in which the multitude of pixel rows are arranged; an image acquisition control section for controlling a signal readout of the light reception section based on a drive clock; and an external signal receiving section, coupled with the image acquisition control section and for receiving an external signal, wherein the external signal receiving section is coupled to a processing unit that generates the external signal, wherein the external signal comprises data specifying an interval of a start time of a signal readout between adjacent pixel rows, wherein the interval of a start time of a signal readout between adjacent pixel rows is calculated by the processing unit for synchronization with a sampling of the object with the illumination light, and where the start time of a signal readout of each pixel row is controlled based on the external signal. [2] Image acquisition device according to claim 1, wherein the interval of a start time of a signal readout between adjacent pixel rows contains a period of signal readout. [3] Image acquisition device according to claim 2, wherein the period of signal readout is variable. [4] Image acquisition device according to claim 3, wherein the interval of a start time of a signal readout between adjacent pixel rows is adjusted by changing the number of cycles in the operating clock, thereby defining the period of the signal readout. [5] Image acquisition system comprising the image acquisition device according to any one of claims 1 to 4 and the computing unit. [6] Image acquisition system according to claim 5, wherein the computing unit is configured such that the speed of movement of the illumination light on the object is entered therein. [7] Image acquisition system according to claim 5, wherein the image acquisition system comprises a light scanning unit for scanning the object with illumination light and an optical system for guiding light away from the object; and wherein the computing unit is configured to capture information regarding the speed of scanning the object with the illumination light from the light scanning unit. [8] Computing unit coupled to the image acquisition device according to any one of claims 1 to 4, and configured to transmit the external signal. [9] Calculation unit according to claim 8, wherein the calculation unit is configured such that the speed of movement of the illumination light on the is entered therein. [10] Calculation unit according to claim 8, wherein the object is scanned by a light scanning unit using the illumination light; and wherein the computing unit is configured to capture information regarding the speed of scanning the object with the illumination light from the light scanning unit.

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