WO2016119122A1 - 基于传感器的投影仪自动调焦方法 - Google Patents

基于传感器的投影仪自动调焦方法 Download PDF

Info

Publication number
WO2016119122A1
WO2016119122A1 PCT/CN2015/071627 CN2015071627W WO2016119122A1 WO 2016119122 A1 WO2016119122 A1 WO 2016119122A1 CN 2015071627 W CN2015071627 W CN 2015071627W WO 2016119122 A1 WO2016119122 A1 WO 2016119122A1
Authority
WO
WIPO (PCT)
Prior art keywords
focusing
sensor
lens
focus
clearest
Prior art date
Application number
PCT/CN2015/071627
Other languages
English (en)
French (fr)
Inventor
那庆林
王金明
麦浩晃
黄彦
蒋海滨
封应平
Original Assignee
神画科技（深圳）有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 神画科技（深圳）有限公司 filed Critical 神画科技（深圳）有限公司
Priority to PCT/CN2015/071627 priority Critical patent/WO2016119122A1/zh
Publication of WO2016119122A1 publication Critical patent/WO2016119122A1/zh

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/53—Means for automatic focusing, e.g. to compensate thermal effects

Definitions

  • the present invention relates to a projector, and more particularly to a sensor-based projector automatic focusing method.
  • the projection system comprises a projection module, an infrared monitoring module, an infrared light source mounted on the projection module, and a focusing device for driving the first lens group to move back and forth; the infrared spot emitted by the infrared light source is preferably projected on the projection
  • the inside or the edge of the projection screen of the module will be transmitted to the infrared monitoring module after being reflected back; by analyzing the infrared spot image emitted by the infrared light source collected by the infrared monitoring module, the control can be sent to the focusing motor.
  • the signal adjusts the first lens group to a suitable position so that the auto focus function can be achieved.
  • the focus is adjusted from the state of staying after the last use, and the definition of the projected image will undergo a search process that gradually becomes better, achieves the best, and gradually deteriorates, and usually starts to deteriorate.
  • the search is stopped, and the clearest focusing parameter when the clearest image is obtained is recorded; then the focus is re-adjusted based on the sharpest focusing parameter, and the current position is directly returned to the position corresponding to the clearest focusing parameter.
  • the present invention solves the problem that the existing projector automatic focusing scheme cannot meet the precise focusing requirements.
  • the technical solution adopted by the present invention to solve the technical problem thereof is: providing A sensor-based projector autofocus method, characterized in that the projector comprises at least one set of lenses that can be moved back and forth within a focus range, and a focus motor that drives the lens to move; A sensor is disposed at a position corresponding to the lower limit edge or the upper limit edge within the effective focus range of the lens, and the position corresponding to the sensor is determined as a focus reference point; when refocusing is required, the following steps are performed automatically. focal:
  • step S1 of the method of the present invention image analysis may be employed. Find and determine the sharpest focus adjustment parameters for the lens when you get the sharpest projected image.
  • the specific steps include:
  • Focusing the lens on the step S12 of the method of the present invention During the process, the sharpness of the projected image undergoes a process of getting better, achieving the best, and gradually degrading, and then recording the sharpest focusing parameter when the clearest image is obtained.
  • step S1 of the method of the present invention ranging method can be employed Find and determine the sharpest focusing parameter of the lens when the sharpest projected image is available, specifically by measuring the projection distance between the lens and the projection screen to determine the clearest focusing parameter.
  • the clearest focusing parameter is the number of steps or the running time of the focusing motor when the clearest image is obtained;
  • the sensor is an electronic sensor, a photoelectric sensor, or an electromagnetic sensor.
  • refocusing is required when any of the following occurs: (1) when the projector is powered on; (2) When the projector detects its own vibration or displacement; (3) by detecting the sharpness of the projected image every predetermined time, it is found that the current projected image is not clear; (4) When the current projection distance is changed by detecting the projection distance every predetermined time.
  • Only one focus sensor may be provided, and is disposed near the lower limit edge or the upper limit edge of the effective focus range of the lens.
  • the first focusing sensor is disposed at a position corresponding to a lower limit edge of the effective focusing range of the lens
  • the second focusing sensor is disposed at an upper edge of the effective focusing range of the lens.
  • the lens needs to pass through the first reference point or the second reference point at least once. Specifically, the lens passes at least one reference point closest to the current position at least once until it stops at the position corresponding to the clearest focusing parameter. .
  • the present invention determines the clearest focusing parameter of the lens first, and then Automatically focus from the reference point corresponding to the focus sensor to the position corresponding to the recorded clearest focus parameter.
  • the advantage of this focusing method is that the mechanical accumulation error due to lens activation and reentry can be eliminated, thereby greatly improving the focusing accuracy. With this solution, the accuracy requirements for the mechanical fit are reduced, which further reduces the manufacturing cost of the projector.
  • Figure 1 is a flow chart of the automatic focusing method of the present invention
  • Figure 2 is a flow chart of automatic focusing when using image analysis
  • FIG. 3 is a schematic diagram of a focusing range of a projector
  • FIG. 4 is a block diagram of the modules in the focusing operation.
  • the lens of the projector can be moved back and forth within the focus range, and the lower arrow line shows the focus range, which is the range in which the lens can move when the projector is focusing.
  • the left side of the figure is the lower limit of the focus range.
  • 301 The right side is the upper limit of the focus range 302; the upper arrow line shows the effective focus range, that is, the image corresponding to the maximum and minimum working distance of the projector can focus on the clear lens movement range, and the left side is the lower limit of the effective focus range.
  • On the right is the upper limit of the effective focus range 304; visible, the effective focus range is smaller than the focus range, that is, the effective focus range is included in the focus range.
  • Position when the clearest projected image is available 305 It is located between the lower limit of the effective focus range 303 and the upper limit of the effective focus range of 304. It may be in different positions depending on the environment.
  • an image analysis method is used to find and determine the clearest focusing parameter, and the focusing process scheme can be A prior utility model of this patent applicant (authorization announcement number: CN203012335U; authorization announcement date: June 19, 2013; application number: 201220730223.X
  • the disclosed autofocus projection system is implemented.
  • a focus sensor is disposed at a position corresponding to the edge, and a lower limit edge corresponding to the focus sensor is determined as a focus reference point.
  • the focus sensor is triggered and adjusted to focus
  • the control module sends out the corresponding sensing signal. That is to say, the focus control module can determine whether the focusing of the lens has reached or passed the reference point by the sensing signal of the focus sensor.
  • the senor may be an electronic sensor, a photoelectric sensor, or an electromagnetic sensor; for example, the receiving end of the photoelectric sensor is installed at the lower limit of the effective focusing range. 303 The position corresponding to the edge is fixed and the light-emitting end of the photoelectric sensor will be on the lens and move synchronously with the lens. When the receiving end and the transmitting end are facing each other, the photoelectric sensor is triggered, so that the sensing signal can be emitted.
  • FIG. 1 A flowchart of the autofocus method of the present invention is shown in FIG. 1. In this embodiment, after starting from step S100,
  • Step S101 it is judged whether refocusing is needed, and if yes, step S102 is performed; otherwise, the detection judgment state is continued.
  • Step S102 Find and determine the clearest focusing parameter of the lens when the clearest projected image is obtained.
  • Step S103 focusing the lens so that it passes the focus reference point at least once. Auto-focusing is completed until the position corresponding to the clearest focusing parameter is stopped.
  • the significance of passing the focus reference point at least once is that step S1
  • the clearest focus adjustment parameter is determined based on the reference point.
  • at least one mechanical error of the lens start occurs, and the acquisition of the sharpest focusing parameter may also result in a cumulative mechanical error caused by the folding of the lens.
  • the focusing motor of the present invention drives the lens to the clearest point of the focusing process, and there is a continuous one-way movement process through the focus reference point until the sharpest point; therefore, the lens start and foldback errors are not included in the In the process of focusing movement, the auto focus is more precise.
  • FIG. 2 A preferred embodiment of the present invention is shown in Fig. 2, and in the present embodiment, starting from step S200.
  • Step S201 it is judged whether refocusing is needed, and if yes, step S202 is performed, otherwise the detection judgment state is continued.
  • Step S202 adjusting the lens outside the effective focus range, that is, FIG. 3
  • Step S203 starting from outside the effective focus range, focusing on the lens , so that it passes through the focus reference point at least once, and detects the sharpness simultaneously.
  • Step S204 Through the condition of synchronous detection, it is judged whether the sharpness has reached the optimum and then starts to deteriorate. Specifically, in the process of focusing from the reference point, the definition of the projected image will gradually become better and achieve the best. a process of progressive deterioration; in this embodiment, When the sharpness of the projected image has gradually deteriorated at the beginning, immediately jump to step S205 to stop the current round of focusing. In the specific implementation, after all the focusing strokes are completed, the process jumps to step S205. Stop this round of focusing. Of course, the latter method consumes more time, and in the embodiment shown in Fig. 2, when the sharpness of the projected image is initially gradually deteriorated, the current focusing is stopped immediately, which reduces the time required for focusing.
  • Step S205 stopping the current round of focusing, and recording the clearest focusing parameter when obtaining the clearest image.
  • the sharpest focusing parameter may be the number of steps, or the running time, or angular displacement of the focusing motor when the sharpest image is obtained.
  • the focus motor can be a stepper motor or a servo motor.
  • Step S206 the lens is adjusted again to be outside the effective focus range.
  • Step S207 starting from outside the effective focus range, focusing on the lens , at least once through the focus reference point, and directly positioned to the position corresponding to the clearest focus parameter, complete the auto focus.
  • the autofocus is performed by using at least two times through the reference point, the first pass
  • the reference point is to synchronously detect the sharpness of the projected image until the clearest image is obtained, and then record the corresponding clearest focusing parameter; the second time from the effective focusing range, focus adjustment is performed.
  • the reference point is directly positioned to the position corresponding to the clearest focusing parameter, and the auto focus is completed.
  • the focus sensor is installed at the lower limit of the effective focus range 303.
  • the position corresponding to the edge can also be installed at the position corresponding to the edge of the upper limit of the effective focus range 304, that is, the upper limit of the effective focus range in FIG.
  • the position corresponding to the edge is the reference point.
  • the first focusing sensor is disposed at the edge of the lower limit 303 of the effective focusing range of the lens, and the second focusing sensor is disposed at the edge of the upper limit 304 of the effective focusing range of the lens;
  • the lower limit edge corresponding to the first focus sensor is determined as the first reference point
  • the upper limit edge corresponding to the second focus sensor is determined as the second reference point;
  • the first focus sensor or the second focus sensor is triggered and sends a corresponding first or second sensor signal to the focus control module
  • the lens can be adjusted back to the reference point closest to the current position, for example, the reference point on the left side in Fig. 3 is closer, so it is better to return to the left reference point, and then Starting from the benchmark Focusing on the lens.
  • step S102 shown in FIG. 1 a distance measuring method may also be employed. Find and determine the sharpest focusing parameter of the lens when the sharpest projected image is available, specifically by measuring the projection distance between the lens and the projection screen to determine the clearest focusing parameter.
  • step S102 shown in FIG. 1 a distance measuring method may also be employed. Find and determine the sharpest focusing parameter of the lens when the sharpest projected image is available, specifically by measuring the projection distance between the lens and the projection screen to determine the clearest focusing parameter.
  • Next steps and Figure 1 The process is the same.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Optics & Photonics (AREA)
  • Automatic Focus Adjustment (AREA)
  • Focusing (AREA)
  • Projection Apparatus (AREA)

Abstract

一种基于传感器的投影仪自动调焦方法，在与投影仪镜头的有效调焦范围下限（301）边缘或上限（302）边缘对应的位置处设有传感器，当需要重新调焦时，先查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数（S102），然后对所述镜头进行调焦，使之至少一次经过所述调焦基准点，直至停止在所述最清晰调焦参数所对应的位置，完成自动调焦（S103）。这种调焦方法的优点是可以消除机械累积误差，大大提高调焦精度。使用这种方案之后，对机械配合的精度要求降低，从而可进一步降低投影仪的制造成本。

Description

基于传感器的投影仪自动调焦方法 技术领域
本发明涉及投影仪，更具体地说，涉及一种基于传感器的投影仪自动调焦方法。
背景技术
传统的投影仪多是采用手动调焦的方式，但也有一些新的投影仪具有自动调焦功能，例如，在本专利申请人的一件在先实用新型（授权公告号： CN203012335U ；授权公告日： 2013 年 6 月 19 日 ；申请号： 201220730223.X ）中，就公开了一种自动调焦的投影系统。该投影系统中包括投影模组、红外监控模组、装于投影模组上的红外光源，以及用于驱动第一镜片组前后移动的调焦装置；红外光源发出的红外光斑最好投射于投影模组的投影画面内部或边缘，并会在反射回来后传送到红外监控模组；通过对红外监控模组采集到的由红外光源发出的红外光斑图片进行分析，即可向调焦马达发出控制信号，调整第一镜片组到合适位置，从而可达到自动调焦的功能。
现有的自动调焦方案中，是从上一次使用后停留的状态开始调焦，投影图像的清晰度会经历逐步变好、达到最佳、逐步变差的搜寻过程，通常会在开始变差之后即停止搜寻，并记录获得所述最清晰图像时的最清晰调焦参数；然后基于这个最清晰调焦参数再重新调焦，从当前位置直接回到最清晰调焦参数所对应的位置。
然而，投影物镜、调焦装置、调焦马达等部分或多或少会存在一些机械累积误差，这些误差会影响调焦精度，导致上述自动调焦方案无法满足精确调焦的要求，或者需要机械配合的精度特别高，才能满足精确调焦的要求。其中，机械误差通常在镜头调焦移动过程中以镜头启动和折返过程中产生的最大。
发明内容
针对现有技术的上述缺陷，本发明要解决现有的投影仪自动调焦方案无法满足精确调焦要求的问题。
本发明解决其技术问题所采用的技术方案是：提供 一种基于传感器的投影仪自动调焦方法，其特征在于，所述投影仪包括至少一组可以在调焦范围内前后移动调焦的镜头，还包括驱动镜头移动的调焦马达；在与所述镜头的有效调焦范围内靠近下限边缘或上限边缘对应的位置处设有传感器，所述传感器所对应的位置被确定为调焦基准点；当需要重新调焦时，按以下步骤进行自动调焦：
S1 、查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数；
S2 、 对所述镜头进行调焦，使之至少 一次经过 所述调焦基准点， 直至停止在所述最清晰调焦参数所对应的位置，完成自动调焦。
在本发明所述方法的 步骤S1中，可采用图像分析法 查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数，具体步骤包括：
S11 、将所述镜头调整到所述有效调焦范围外；
S12 、从所述有效调焦范围外开始 针对所述镜头进行调焦 ，至少一次经过所述调焦基准点，并记录获得所述最清晰图像时的最清晰调焦参数。
在本发明所述方法的所述步骤 S12 对所述镜头进行调焦 过程中，所述投影图像的清晰度会经历逐步变好、达到最佳、逐步变差的过程，再记录获得所述最清晰图像时的最清晰调焦参数。
在本发明所述方法的 步骤S1中，可采用测距法 查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数，具体是通过测量镜头与投影屏幕之间的投影距离，进而确定所述最清晰调焦参数。
在本发明所述的方法中， 所述 最清晰 调焦参数为 获得所述最清晰图像时调焦马达的步数、或运行时间； 所述传感器是电子传感器 、光电传感器、或电磁传感器。
在本发明所述的方法中，当出现以下任一情况时可判定为需要重新调焦：（ 1 ）投影仪开机启动时；（ 2 ）投影仪检测到自身的振动或位移时；（ 3 ）通过每隔预定时间检测投影图像的清晰度发现当前投影图像不清晰时；（ 4 ）通过每隔预定时间检测投影距离发现当前投影距离发生变化时。
在本发明所述的方法中， 可只设有一个调焦传感器，并设于靠近所述镜头的有效调焦范围下限边缘或上限边缘所对应的位置。
在本发明所述的方法中，可 设有两个调焦传感器，第一调焦传感器设于靠近所述镜头的有效调焦范围下限边缘所对应的位置，第二调焦传感器设于靠近所述镜头的有效调焦范围上限边缘所对应的位置；此时，所述第一调焦传感器所对应的下限边缘被确定为第一基准点，所述第二调焦传感器所对应的上限边缘被确定为第二基准点。
当设置两个 调焦传感器时，在所述步骤 S2 中，所述镜头需要至少一次通过第一基准点或第二基准点。具体来说，将所述镜头至少一次经过离当前位置最近的那一个 基准点， 直至停止在所述最清晰调焦参数所对应的位置 。
从本发明的技术方案可以看出，本发明通过先确定 镜头的最清晰调焦参数，再 从调焦传感器所对应的基准点开始直接定位到已记录的 最清晰调焦参数所对应的位置来进行自动调焦 ， 这种调焦方法的优点是可以消除源于镜头启动和折返而产生的机械累积误差，进而大大提升调焦精度。使用这种方案之后，对机械配合的精度要求降低，从而可进一步降低投影仪的制造成本。
附图说明
下面将结合附图及实施例对本发明作进一步说明，附图中：
图1是本发明自动调焦方法的流程图；
图2是采用采用图像分析法时的自动调焦流程图；
图3是投影仪的调焦范围示意图；
图4是 调焦工作中各模块的原理框图。
具体实施方式
以上实施例只为说明本发明的技术构思及特点，其目的在于让熟悉此项技术的人士能够了解本发明的内容并据此实施，并不能限制本发明的保护范围。凡跟本发明权利要求范围所做的均等变化与修饰，均应属于本发明权利要求的涵盖范围。
如图 3 所示，投影仪的镜头可以在调焦范围内前后移动调焦，下部箭头线显示的是其调焦范围，即投影仪在调焦时镜头可移动的范围，图中左边是调焦范围下限 301 、右边是调焦范围上限 302 ；上部箭头线显示的是其有效调焦范围，即投影仪的最大最小工作距离对应的图像能聚焦清晰的镜头移动范围，左边是有效调焦范围下限 303 、右边是有效调焦范围上限 304 ；可见，有效调焦范围要小于调焦范围，也即有效调焦范围包含于调焦范围之内。可获得最清晰投影图像时的位置 305 位于有效调焦范围下限 303 、有效调焦范围上限 304 之间，可能因使用环境不同而位于不同的位置。
本发明一个优选实施例中，采用图像分析法 查找并确定最清晰调焦参数， 该调焦过程方案可以在 本专利申请人的一件在先实用新型（授权公告号： CN203012335U ；授权公告日： 2013 年 6 月 19 日；申请号： 201220730223.X ）所公开的自动调焦的投影系统上得到实施。
如图 4 所示，为了实施本发明的技术方案，还需要在与镜头的有效调焦范围下限 303 边缘对应的位置处设置一个调焦传感器，该调焦传感器所对应的下限边缘被确定为调焦基准点，当针对镜头进行调焦并到达该基准点时，调焦传感器被触发并向调焦控制模块发出相应的传感信号。也就是说，调焦控制模块可通过调焦传感器的传感信号来确定对镜头的调焦是否达到或经过了基准点。具体实施时，其中的传感器可以是电子传感器、光电传感器、或电磁传感器；例如，将光电传感器的接收端装在有效调焦范围下限 303 边缘对应的位置处且固定不动，再将光电传感器的发光端将在镜头上并随镜头同步运动，当接收端与发射端正对时，光电传感器被触发，从而可发出传感信号。
本发明自动调焦方法的流程图如图1所示， 在本实施例中，从步骤 S100 开始后，
步骤 S101 ，判断是否需要重新调焦，如果是则执行步骤 S102 ，否则继续保持检测判断状态。具体来说， 当出现以下任一情况时，可判定为需要重新调焦：（1）投影仪开机启动时；（2）投影仪检测到自身的振动或位移时，具体可通过投影仪的内置传感器来感测是否有振动或位移；（3）通过每隔预定时间 检测投影图像的清晰度发现当前投影图像不清晰时，例如每隔 1 分钟检测一次； （4） 通过每隔预定时间检测投影距离发现当前投影距离发生变化时。
步骤 S102 ，查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数。
步骤 S103 ， 对镜头进行调焦，使之至少 一次经过 所述调焦基准点， 直至停止在所述最清晰调焦参数所对应的位置，完成自动调焦。
本发明中，至少一次经过调焦基准点的意义在于，步骤 S1 中最清晰调焦参数是基于所述基准点所确定。在调焦过程中，至少会发生一次镜头启动的机械误差，同时最清晰调焦参数的获得也可能用到若干此镜头折返而产生累积机械误差。但本发明中的调焦马达驱动镜头到达最清晰点的调焦过程，都会有经过调焦基准点直到最清晰点的连续单向移动过程；所以，镜头启动和折返的误差不会被包含在调焦移动的过程里，从而使自动调焦更加精准。
本发明一个优选实施例如图2所示， 在本实施例中，从步骤 S200 开始。
步骤 S201 ，判断是否需要重新调焦，如果是则执行步骤 S202 ，否则继续保持检测判断状态。
步骤 S202 ，将镜头调整到有效调焦范围外，也就是向图 3 中的左侧调整直至调焦控制模块收到传感信号，然后再向左调整，此时可确保镜头调整到有效调焦范围外，即图 3 中调焦范围下限 301 与有效调焦范围下限 303 之间。
步骤 S203 ，从有效调焦范围外开始 针对镜头进行调焦 ，使之至少一次经过调焦基准点，并同步检测清晰度。
步骤 S204 ，通过同步检测的情况，判断清晰度是否达到最佳后开始变差，具体来说，在从基准点开始进行调焦的过程中，投影图像的清晰度会经历逐步变好、达到最佳、逐步变差的过程；本实施例中， 在 投影图像的清晰度刚开始逐步变差时，立即跳到步骤 S205 停止本轮调焦。具体实施时，还可以在完成全部调焦行程之后，才跳到步骤 S205 停止本轮调焦。当然，后一种方式会耗用更多时间，而图 2 所示实施例中 在 投影图像的清晰度刚开始逐步变差时，立即停止本轮调焦，可减少调焦所需的时间。
步骤 S205 ，停止本轮调焦，并记录获得最清晰图像时的最清晰调焦参数。 当投影仪中使用调焦马达来驱动投影物镜进行调焦时， 最清晰 调焦参数可以是 获得所述最清晰图像时调焦马达的步数、或运行时间、或角位移。 调焦马达可以是步进马达、或伺服马达。
步骤 S206 ，再次镜头调整到有效调焦范围外。
步骤 S207 ，从有效调焦范围外开始 针对镜头进行调焦 ，使之至少一次经过调焦基准点，并直接定位到所述最清晰调焦参数所对应的位置，完成自动调焦。
从上述实施例可以看出，针对可自动调焦的投影仪，其中采用至少两次经过基准点的方式进行自动调焦，第一次经过 基准点是对投影图像的清晰度进行同步检测，直至获得到最清晰图像，再记录对应的最清晰调焦参数； 第二次从有效调焦范围外 开始进行调焦， 经过 基准点，并直接定位到所述最清晰调焦参数所对应的位置，完成自动调焦。这种调焦方法的优点是可以消除机械累积误差，进而大大提升调焦精度。使用这种方案之后，对机械配合的精度要求降低，从而可进一步降低投影仪的制造成本。
上述实施例中，只有一个调焦传感器，且是将调焦传感器装于有效调焦范围下限 303 边缘对应的位置处。具体实施时，还可以将这个调焦传感器装于有效调焦范围上限 304 边缘对应的位置处 ，也即以图3中 有效调焦范围上限 304 边缘对应的位置处为基准点。
另外，还 可以设两个调焦传感器，第一调焦传感器设于镜头的有效调焦范围下限303边缘，第二调焦传感器设于镜头的有效调焦范围上限304边缘；此时。此时，第一调焦传感器所对应的下限边缘被确定为第一基准点，第二调焦传感器所对应的上限边缘被确定为第二基准点；当针对镜头进行调焦并到达所述第一基准点或第二基准点时，第一调焦传感器或第二调焦传感器被触发并向调焦控制模块发出相应的第一传感信号或第二传感信号 ；当需要回到基准点时，可将镜头调整回到离当前位置最近的那一个 基准点，例如在图3中左侧的基准点更近，所以最好是回到左侧基准点， 再从该基准点开始 针对镜头进行调焦。
本发明并不限于上述实施例， 例如，在图1所示的步骤S102中，还可采用测距法 查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数，具体是通过测量镜头与投影屏幕之间的投影距离，进而确定所述最清晰调焦参数。后续步骤与图 1 的流程相同。

Claims (10)

  1. 一种基于传感器的投影仪自动调焦方法，其特征在于，所述投影仪包括至少一组可以在调焦范围内前后移动调焦的镜头，还包括驱动镜头移动的调焦马达；在与所述镜头的有效调焦范围内靠近下限边缘或上限边缘对应的位置处设有传感器，所述传感器所对应的位置被确定为调焦基准点；当需要重新调焦时，按以下步骤进行自动调焦：
    S1 、查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数；
    S2 、 对所述镜头进行调焦，使之至少 一次经过 所述调焦基准点， 直至停止在所述最清晰调焦参数所对应的位置，完成自动调焦。
  2. 根据权利要求 1 所述的 基于传感器的投影仪自动调焦方法，其特征在于，所述步骤S1中，采用图像分析法 查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数，具体步骤包括：
    S11 、将所述镜头调整到所述有效调焦范围外；
    S12 、从所述有效调焦范围外开始针对所述镜头进行调焦，至少一次经过所述调焦基准点，并记录获得所述最清晰图像时的最清晰调焦参数。
  3. 根据权利要求 2 所述的基于传感器的投影仪自动调焦方法，其特征在于，在所述步骤 S12 对所述镜头进行调焦过程中，所述投影图像的清晰度会经历逐步变好、达到最佳、逐步变差的过程，再记录获得所述最清晰图像时的最清晰调焦参数。
  4. 根据权利要求 1 所述的 基于传感器的投影仪自动调焦方法，其特征在于，所述步骤S1中，采用测距法 查找并确定可获得最清晰投影图像时镜头的最清晰调焦参数，具体是通过测量镜头与投影屏幕之间的投影距离，进而确定所述最清晰调焦参数。
  5. 根据权利要求 1-4 中任一项所述的 基于传感器的投影仪自动调焦方法，其特征在于，所述 最清晰 调焦参数为 获得所述最清晰图像时调焦马达的步数、或运行时间； 所述传感器是电子传感器 、光电传感器、或电磁传感器。
  6. 根据权利要求 1-4 中任一项所述的基于传感器的投影仪自动调焦方法，其特征在于，当出现以下任一情况时可判定为需要重新调焦：（ 1 ）投影仪开机启动时；（ 2 ）投影仪检测到自身的振动或位移时；（ 3 ）通过每隔预定时间检测投影图像的清晰度发现当前投影图像不清晰时；（ 4 ）通过每隔预定时间检测投影距离发现当前投影距离发生变化时。
  7. 根据权利要求 1-4 中任一项所述的 基于传感器的投影仪自动调焦方法，其特征在于，其中只设有一个调焦传感器，并设于靠近所述镜头的有效调焦范围下限边缘或上限边缘所对应的位置。
  8. 根据权利要求 1-4 中任一项所述的 基于传感器的投影仪自动调焦方法，其特征在于，其中设有两个调焦传感器，第一调焦传感器设于靠近所述镜头的有效调焦范围下限边缘所对应的位置，第二调焦传感器设于靠近所述镜头的有效调焦范围上限边缘所对应的位置；此时，所述第一调焦传感器所对应的下限边缘被确定为第一基准点，所述第二调焦传感器所对应的上限边缘被确定为第二基准点。
  9. 根据权利要求 8 所述的 基于传感器的投影仪自动调焦方法，其特征在于，在所述步骤 S2 中，所述镜头需要至少一次通过第一基准点或第二基准点。
  10. 根据权利要求 9 所述的 基于传感器的投影仪自动调焦方法，其特征在于，在所述步骤 S2 中，将所述镜头至少一次经过离当前位置最近的那一个 基准点， 直至停止在所述最清晰调焦参数所对应的位置 。
PCT/CN2015/071627 2015-01-27 2015-01-27 基于传感器的投影仪自动调焦方法 WO2016119122A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2015/071627 WO2016119122A1 (zh) 2015-01-27 2015-01-27 基于传感器的投影仪自动调焦方法

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2015/071627 WO2016119122A1 (zh) 2015-01-27 2015-01-27 基于传感器的投影仪自动调焦方法

Publications (1)

Publication Number Publication Date
WO2016119122A1 true WO2016119122A1 (zh) 2016-08-04

Family

ID=56542125

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/071627 WO2016119122A1 (zh) 2015-01-27 2015-01-27 基于传感器的投影仪自动调焦方法

Country Status (1)

Country Link
WO (1) WO2016119122A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112799275A (zh) * 2019-11-13 2021-05-14 青岛海信激光显示股份有限公司 一种超短焦投影镜头调焦方法、调焦系统及投影仪

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5552847A (en) * 1991-10-25 1996-09-03 Nikon Corporation Lens barrel
US20090296050A1 (en) * 2008-05-30 2009-12-03 Canon Kabushiki Kaisha Projection type display
US20120105709A1 (en) * 2009-05-11 2012-05-03 Panasonic Corporation Camera, portable terminal device, and lens position control method
CN102469256A (zh) * 2010-11-02 2012-05-23 索尼公司 成像设备、成像方法和程序
CN203012335U (zh) * 2012-11-30 2013-06-19 神画科技（深圳）有限公司 自动调焦的投影系统
CN104570569A (zh) * 2015-01-27 2015-04-29 神画科技（深圳）有限公司 基于传感器的投影仪自动调焦方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5552847A (en) * 1991-10-25 1996-09-03 Nikon Corporation Lens barrel
US20090296050A1 (en) * 2008-05-30 2009-12-03 Canon Kabushiki Kaisha Projection type display
US20120105709A1 (en) * 2009-05-11 2012-05-03 Panasonic Corporation Camera, portable terminal device, and lens position control method
CN102469256A (zh) * 2010-11-02 2012-05-23 索尼公司 成像设备、成像方法和程序
CN203012335U (zh) * 2012-11-30 2013-06-19 神画科技（深圳）有限公司 自动调焦的投影系统
CN104570569A (zh) * 2015-01-27 2015-04-29 神画科技（深圳）有限公司 基于传感器的投影仪自动调焦方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112799275A (zh) * 2019-11-13 2021-05-14 青岛海信激光显示股份有限公司 一种超短焦投影镜头调焦方法、调焦系统及投影仪
CN112799275B (zh) * 2019-11-13 2023-01-06 青岛海信激光显示股份有限公司 一种超短焦投影镜头调焦方法、调焦系统及投影仪

Similar Documents

Publication Publication Date Title
CN104570569B (zh) 基于传感器的投影仪自动调焦方法
CN104570568B (zh) 投影仪自动调焦方法
US7872814B2 (en) Optical device, control method therefor, and program for implementing the control method
EP0694799B1 (en) Optical apparatus
US7990626B2 (en) Lens barrel and image capturing apparatus
WO2019037326A1 (zh) 投影仪自动调焦方法及投影仪
CN105721753A (zh) 镜头组装方法和镜头组装装置
WO2016119122A1 (zh) 基于传感器的投影仪自动调焦方法
CN100401134C (zh) 数字照相机的调整方法及其调整装置
WO2016095235A1 (zh) 投影仪自动调焦方法
CN102147521B (zh) 摄像镜头、摄像设备和摄像设备的控制方法
JP2911653B2 (ja) 絞り装置を有する光学機器およびレンズ鏡筒
JP2694155B2 (ja) ズームレンズ装置
JP2000206585A (ja) 交換レンズ
JP2775484B2 (ja) ズームレンズ鏡胴およびそのフランジバック調整方法
JP3655875B2 (ja) カメラの測距装置
JP2013080079A (ja) レンズ駆動機構
WO2008018454A1 (fr) Dispositif imageur
JPH05113533A (ja) ズームレンズのレンズ位置制御装置
JPH0210514Y2 (zh)
JPH0283510A (ja) 自動合焦システム
JP2586471B2 (ja) カメラ
JPH03231212A (ja) バックフォーカス調整装置及びバックフォーカス調整方法
KR19990015441A (ko) Ｏｈｐ의 자동 초점 조정장치 및 그 방법
JP2020079873A (ja) 撮像装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15879333

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15879333

Country of ref document: EP

Kind code of ref document: A1