JP6070375B2 - FOCUS ADJUSTMENT DEVICE, PROJECTION DEVICE, AND METHOD FOR CONTROLLING PROJECTION DEVICE - Google Patents

Description

The present invention, focus adjustment equipment for adjusting the focus of the image projected onto a projection medium, and to a method of controlling a projection device and a projection device.

  2. Description of the Related Art Conventionally, a projection device that drives a display element based on an input image signal and projects an image related to the image signal onto a projection medium such as a screen or a wall surface is known. In such a projection apparatus, a technique for automatically adjusting a focal length (hereinafter referred to as autofocus) when an image is projected is known. Patent Document 1 discloses a projector that performs autofocus control based on a distance sensor output or a contrast of a projected image.

  As the distance measuring sensor, an optical sensor that performs distance measurement using reflection of a laser beam or infrared rays is widely used. In the distance measuring method using the optical distance measuring sensor, distance measurement is performed based on the difference between the light beam emitted from the light emitting unit and the reflected light reflected by the measurement object (projected medium). The reflected light is detected by a photo sensor using a photodiode or the like.

JP 2005-121941 A

  The output of the optical distance measuring sensor is not always stable due to the influence of disturbance, environment, etc., and always varies minutely. For this reason, even if the distance between the projection apparatus and the projection medium is fixed, the focusing distance by autofocus continuously fluctuates slightly reflecting the fluctuation of the distance measuring sensor output. This small change in autofocus does not cause an unpleasant sensation to the projected image projected on the projection medium.

  However, the continuous minute fluctuation of autofocus causes the focus lens system included in the projection optical system to continue to be driven minutely, which promotes wear and fatigue of mechanical parts such as gears that drive the lens system. There was a point. This is a factor that lowers the reliability of the device.

  On the other hand, a large margin for the output of the distance measuring sensor can be considered so that a minute variation in the output of the distance measuring sensor can be ignored. However, in this case, it is difficult to focus properly by autofocus, and the projected image projected on the projection medium may be uncomfortable to the eye.

  The present invention has been made in view of the above, and an object thereof is to enable appropriate control of autofocus in a projection apparatus.

In order to solve the above-described problems and achieve the object, the present invention provides a distance value output unit that outputs a distance value indicating the distance from the measured projection unit to the projection medium, and a light that passes through the projection unit. A focus adjustment unit that adjusts the focus and a distance value as a first distance value, and detects a first deviation from the in-focus state of the light projected on the projection medium by the projection unit based on the first distance value And a focus adjustment drive unit that drives the focus adjustment unit so that the value indicating the first deviation becomes 0, and the distance value is used as the second distance value, and the light is focused based on the second distance value. A determination unit that detects a second deviation from the threshold and determines whether or not a value indicating the second deviation is less than a threshold value, and a threshold value is the first value and a value indicating the second deviation is a first value If the first is less than the value state is determined the determination unit to have continued a predetermined time or longer, than the first value the threshold value Set Kii second value, the updating of the first distance value is stopped, the threshold value is a second value, and is being changed in the projection direction by the projection unit, and shows a second deviation If the values determined the determination unit to be the second value or more, the threshold value is set to a first value, and having a control unit to restart the update of the first distance value.

Further, the present invention provides a changing step of changing a projection direction of light projected from the projection unit, a distance measuring step of measuring a distance from the projection unit to the projection medium and outputting a distance value, and the distance value. Light that is used as a first distance value, detects a first deviation from the in-focus state of light projected onto the projection medium by the projection unit based on the first distance value, and passes through the projection unit A focus adjustment step of adjusting the focus of the light so that a value indicating the first deviation becomes 0, and using the distance value as a second distance value, and focusing the light based on the second distance value A first determination step of detecting a second deviation from the first and determining whether or not a value indicating the second deviation is less than a threshold, and a value indicating the second deviation is less than the threshold Second determination for determining whether or not the state has continued for a predetermined time or more And the threshold value is a first value, the first determination step determines that the value indicating the second deviation is less than the first value, and the second determination step When it is determined that the state in which the value indicating the second deviation is less than the first value has continued for a predetermined time or more, the threshold value is set to a second value that is greater than the first value. A first threshold value changing step, wherein the threshold value is the first value, and the first determination step determines that the value indicating the second deviation is less than the first value, and When it is determined in the second determination step that the value indicating the second deviation is less than the first value has continued for a predetermined time or longer, the first adjustment used in the focus adjustment step A first control step for stopping the updating of the distance value; The threshold value is the second value, and the first determination step determines that the value indicating the second deviation is greater than or equal to the second value, and the projection direction is being changed in the change step. If there is, a second threshold value changing step for setting the threshold value from the second value to the first value, and the threshold value is the second value. The first distance value that has been stopped in the first control step when the value indicating the deviation is determined to be greater than or equal to the second value and the projection direction is being changed in the change step. And a second control step for restarting the update.

  According to the present invention, there is an effect that it is possible to appropriately control autofocus in the projection apparatus.

FIG. 1 is a diagram illustrating an example of an external appearance of a projector device applicable to the embodiment. FIG. 2 is a diagram for explaining the rotation driving of the drum unit by the drum driving unit applicable to the embodiment. FIG. 3 is a diagram for explaining each posture of the drum portion applicable to the embodiment. FIG. 4 is a block diagram illustrating a configuration example of the circuit unit and the optical engine unit 110 of the projector device according to the embodiment. FIG. 5 is a block diagram showing a configuration of an example of the emission optical system. FIG. 6 is a block diagram illustrating a configuration of an example of the lens control unit. FIG. 7 is a diagram for schematically explaining the focus adjustment control by the focus adjustment unit according to the embodiment. FIG. 8 is a flowchart illustrating an example of a register control method by the determination unit. FIG. 9 is a flowchart illustrating another example of the register control method by the determination unit.

  A preferred embodiment of a projection apparatus according to the present invention will be described below with reference to the drawings. Specific numerical values and appearance configurations shown in the embodiments are merely examples for facilitating understanding of the present invention, and do not limit the present invention unless otherwise specified. Detailed explanation and illustration of elements not directly related to the present invention are omitted.

<Appearance of projection device>
FIG. 1 is a diagram showing an example of the appearance of a projection apparatus (projector apparatus) 1 applicable to the embodiment of the present invention. 1A is a perspective view of the projector device 1 viewed from the first surface side where the operation unit is provided, and FIG. 1B is a perspective view of the projector device 1 from the second surface side facing the first surface. FIG. The projector device 1 includes a drum unit 10 and a base 20. The drum unit 10 is a rotating body that can be rotationally driven with respect to the base 20. The base 20 includes a support unit that rotatably supports the drum unit 10 and a circuit unit that performs various controls such as rotation drive control and image processing control of the drum unit 10.

  The drum unit 10 is supported so as to be rotationally driven by a rotating shaft attached to a bearing made of a bearing or the like provided inside side plate portions 21a and 21b which are a part of the base 20. Inside the drum unit 10, a light source, a display element that modulates light emitted from the light source according to image data, a drive circuit that drives the display element, and light that is modulated by the display element are projected to the projection unit 12 (hereinafter, An optical engine unit including an optical system that projects outside from a projection lens 12 is provided. The optical engine unit includes a focus adjustment mechanism that adjusts the focus of the image projected from the projection lens 12 onto the projection medium.

  The drum part 10 is provided with a window part 11 and a window part 13. The window portion 11 is provided so that light projected from the projection lens 12 is irradiated to the outside. The window portion 13 is provided so that a distance sensor for performing a distance measurement process for deriving a distance to the projection medium using, for example, infrared rays can be operated. The distance sensor, for example, emits infrared light that is modulated in a predetermined manner, receives reflected light from the projected medium of the emitted infrared light, and outputs a detection signal that detects a difference between the emitted light and the reflected light. By controlling the focus adjustment mechanism of the optical engine unit based on this detection signal, the focus adjustment of the image projected from the projection lens 12 onto the projection medium is performed.

  The distance sensor is not limited to infrared rays, but may be one using a laser beam. The distance sensor is not limited to an optical sensor using infrared light or laser light, but may be a method using ultrasonic waves.

  Inside the base 20, there are provided various substrates and power supply units of a circuit unit to be described later, a drum driving unit for rotationally driving the drum unit 10 as will be described later, and the like. On the first surface side of the base 20, the projector device 1 is remotely controlled by using an operation unit 14 for inputting various operations for the user to control the projector device 1 and a remote controller (not shown). And a receiver 15 for receiving a signal transmitted from the remote controller. The operation unit 14 includes various operators that receive user operation inputs, a display unit for displaying the state of the projector device 1, and the like.

  The base 20 is provided with intake / exhaust ports 16a, 16b and 17 for performing intake / exhaust for heat dissipation by the fan. The intake / exhaust ports 16a and 16b do not decrease the heat dissipation efficiency in the drum unit 10 even when the drum unit 10 is rotationally driven and the intake / exhaust port 22a of the drum unit 10 faces the base 20 side. It is used for intake or exhaust.

<Drum section rotation drive>
FIG. 2 is a diagram for explaining the rotational driving of the drum unit 10 by the drum driving unit 32 provided on the base 20. FIG. 2 is a diagram showing the configuration of the drum 30 with the cover of the drum unit 10 removed and the drum driving unit 32 provided on the base 20. The drum 30 is provided with a window portion 34 corresponding to the window portion 11 and a window portion 33 corresponding to the window portion 13. The drum 30 has a rotating shaft 36, and is attached to the bearing 37 using a bearing provided on the support portions 31 a and 31 b by the rotating shaft 36 so as to be rotationally driven.

  On one surface perpendicular to the rotation shaft 36 of the drum 30, a gear 35 is provided on the circumference. The drum 30 is rotationally driven through the gear 35 by the drum driving unit 32 provided in the support unit 31b. The protrusions 46 a and 46 b on the inner peripheral portion of the gear 35 are provided for detecting the start point and the end point of the rotation operation of the drum 30. The drum driving unit 32 includes a motor, and can rotate the drum 30 according to the rotation of the motor. As the motor, for example, a stepping motor that performs rotation control for each predetermined angle by a drive pulse can be applied.

  Photo interrupters 51a and 51b are provided for the support portion 31b. The photo interrupters 51a and 51b detect protrusions 46b and 46a provided on the inner periphery of the gear 35, respectively. Output signals from the photo interrupters 51a and 51b are supplied to a rotation control unit 103 described later. In this example, when the protrusion 46b is detected in the photo interrupter 51a, the rotation control unit 103 determines that the posture of the drum 30 is the posture that has reached the end point of the rotation operation. Further, when the protrusion 46a is detected in the photo interrupter 51b, the rotation control unit 103 determines that the posture of the drum 30 is the posture that has reached the starting point of the rotation operation.

  Hereinafter, from the position where the protrusion 46a is detected on the photo interrupter 51b to the position where the protrusion 46b is detected on the photo interrupter 51a, the direction in which the drum 30 rotates through the arc having the longer length on the circumference of the drum 30 Is the positive direction. That is, the rotation angle of the drum 30 increases in the positive direction.

  In this example, the photointerrupter 51a and the photointerrupter 51a and the photointerrupter 51a and the detection position where the photointerrupter 51a detects the protrusion 46b sandwich the rotating shaft 36 so that the angle between them is 330 °. 51b and protrusions 46a and 46b are arranged, respectively.

  When a stepping motor is applied as the motor, the attitude of the drum 30 is specified based on the detection timing of the protrusion 46a by the photo interrupter 51b and the number of drive pulses for driving the motor, and the projection angle by the projection lens 12 is obtained. it can.

  In the configuration as described above, the initial posture of the drum unit 10 is a posture in which the projection direction by the projection lens 12 is perpendicular to the bottom surface of the base 20. FIG. 3A shows the state of the drum unit 10 in the initial posture. In this example, the protrusion 46a is detected on the photo interrupter 51b in the initial posture, and the rotation control unit 103 described later determines that the drum 30 has reached the starting point of the rotation operation. The projection direction refers to the direction of the optical axis of the light projected from the projection lens 12.

  In addition, the distance sensor 60 is provided corresponding to the window part 13 so that it may be illustrated in FIG. 3A and FIGS. 3B, 3C, and 3D described later. The distance sensor 60 is configured to emit infrared rays in the same direction as the projection direction by the projection lens 12. As described above, the focus adjustment mechanism of the optical engine unit 110, which will be described later, is controlled based on the detection signal output from the distance sensor 60, and the focus adjustment of the image projected on the projection medium is performed by the projection lens 12.

  In the following description, unless otherwise specified, “the direction of the drum unit 10” and “the angle of the drum unit 10” are synonymous with “the projection direction by the projection lens 12” and “the projection angle by the projection lens 12”, respectively. And

  For example, when the projector device 1 is activated, the drum unit 10 rotates from the initial posture shown in FIG. 3A in the direction indicated by the arrow A in FIG. The drum driving unit 32 illustrated in FIG. 2 starts to rotate the drum unit 10. The direction of rotation of the drum unit 10 may be opposite to the arrow A. As the drum unit 10 rotates, the projection direction of the projection lens 12 changes. In the example of FIG. 3, the projection direction (projection angle) of the projection lens 12 is the front side (see FIG. 3B) and the upper side (see FIG. 3C) of the projector device 1 as the drum unit 10 rotates. And it changes in order of the back side (refer to Drawing 3 (d)). In the projector device 1 according to the embodiment, the protrusion 46b is detected on the photo interrupter 51a, and it is determined by the rotation control unit 103 described later that the end point of the rotation operation of the drum 30 has been reached.

  In addition, the projection angle of the projection lens 12 when the projection direction by the projection lens 12 faces the front side and is horizontal with respect to the bottom surface of the base 20 is defined as a projection angle of 0 °. FIG. 3B shows the posture of the drum unit 10 (projection lens 12) when the projection angle is 0 °. Hereinafter, the posture of the drum unit 10 (projection lens 12) having the projection angle θ with reference to the posture with a projection angle of 0 ° is referred to as a θ posture. FIG. 3C shows the posture when the projection angle is 90 °, and FIG. 3D shows the posture when the projection angle is 180 °.

  For example, assume that image data is input and the light source is turned on when the drum unit 10 is in the posture shown in FIG. In the drum unit 10, the light emitted from the light source is modulated in accordance with the image data by the display element driven by the drive circuit and is incident on the optical system. Then, light modulated in accordance with the image data is projected from the projection lens 12 and irradiated onto a projection medium such as a screen or a wall surface. By operating the operation unit 14 or the like, the user rotates the drum unit 10 around the rotation shaft 36 while changing the projection direction of the projection lens 12 while projecting from the projection lens 12 based on the image data. be able to.

  Even while the drum unit 10 is rotated and the projection direction is changed, the light emitted from the projection lens 12 is projected onto the projection medium, and the image according to the image data is projected onto the projection medium while the projection position is moved. Projected. In addition, while the projection direction is changed, the distance measurement process using the detection signal output from the distance sensor 60 and the focus adjustment process based on the result of the distance measurement process are executed.

  In the embodiment, the projector device 1 rotates the drum unit 10 as shown in, for example, FIGS. 3B to 3D while performing the projection, thereby projecting the projection angle by the projection lens 12. Accordingly, the projection area in the image data can be changed (moved). As a result, the content of the projected image and the change in the projection position of the projected image on the projection medium, and the content and position of the image area cut out as an image to be projected in the entire image area related to the input image data Change can be matched. Therefore, the user can intuitively grasp which area of all the image areas related to the input image data is projected based on the position of the projected image on the projection medium, and the projected image. It is possible to intuitively perform operations for changing the contents of the.

  When the user performs an operation to instruct the operation unit 14 to stop the projection of the projection image by the projector device 1 and stops the projector device 1, the rotation of the drum unit 10 is controlled so as to return to the initial posture. When it is detected that the light source is turned off and the projection direction of the projection lens 12 is directed perpendicular to the bottom surface of the base 20 and returns to the initial posture after the time set for cooling the light source has elapsed. The power is turned off. By turning off the power after the projection direction of the projection lens 12 is set to be perpendicular to the bottom surface of the base, it is possible to prevent the projection lens 12 from becoming dirty when not in use.

<Internal configuration of projector device>
Next, a configuration for realizing the operation of the projector device 1 according to the embodiment as described above will be described. FIG. 4 shows an exemplary configuration of the circuit unit provided in the base 20 and the optical engine unit 110 provided in the drum unit 10 in the projector device 1.

  The optical engine unit 110 includes a light source 111, a display element 112, an emission optical system 113, a display element driving circuit 114, and a distance sensor 60. The light source 111 includes, for example, three LEDs (Light Emitting Diodes) that emit red (R), green (G), and blue (B), respectively. The RGB light emitted from the light source 111 is applied to the display element 112 via an optical system (not shown).

  The display element 112 is a transmissive liquid crystal display element, for example, and has a size of horizontal 1280 pixels × vertical 800 pixels. The display element 112 is not limited to this, and may be configured by, for example, a reflective liquid crystal display element using LCOS (Liquid Crystal on Silicon) or a DMD (Digital Micromirror Device). In that case, the projector apparatus is configured by an optical system and a drive circuit corresponding to a display element to be applied. Further, the size of the display element 112 is not limited to the above.

  The display element 112 is driven by the display element driving circuit 114, modulates and transmits light of each color of RGB according to image data, and emits the light. That is, the display element 112 functions as a light modulation unit that modulates light of each RGB color according to image data. The RGB colors 1120 emitted from the display element 112 and modulated according to the image data are incident on the emission optical system 113 and projected from the projection lens 12 included in the emission optical system 113 to the outside of the projector apparatus 1.

  FIG. 5 is a block diagram illustrating a configuration of an example of the emission optical system 113. The emission optical system 113 includes the projection lens 12, a focus adjustment unit 1130, and a lens driving unit 1131. The focus adjustment unit 1130 includes, for example, a plurality of combined lenses, and adjusts the focus of light passing therethrough according to the driving of the lens driving unit 1131. For example, the lens driving unit 1131 drives some of the plurality of lenses included in the focus adjustment unit 1130 according to the focus control signal, and adjusts the focus of the light passing through the focus adjustment unit 1130 on the projection medium. . The lens driving unit 1131 outputs lens position information indicating the position of the lens driven to adjust the focus.

  As described above, the optical engine unit 110 is provided in the drum unit 10 that can be rotated by the rotation driving unit 105. The rotation drive unit 105 includes the drum drive unit 32 described with reference to FIG. 2 and the gear 35 that is the configuration on the drum unit 10 side, and rotates the drum unit 10 by using the rotation of the motor. That is, the projection direction of the projection lens 12 is changed by the rotation driving unit 105.

  The circuit unit of the projector device 1 includes an image processing unit 100, a distance value output unit 101, a lens control unit 102, a rotation control unit 103, a rotation drive unit 105, and an overall control unit 120.

  Image data of a still image or a moving image is input to the projector device 1 and supplied to the image processing unit 100. The image processing unit 100 performs image processing on the supplied image data as necessary and stores it in a memory (not shown). Image processing performed by the image processing unit 100 includes keystone correction, size conversion, edge enhancement, luminance adjustment, hue adjustment, and the like. The image processing unit 100 cuts out image data of an image area corresponding to angle information supplied from the rotation control unit 103 described later from the image data stored in the memory. At that time, the image processing unit 100 performs predetermined image processing on the cut-out image data and outputs it.

  The image data output from the image processing unit 100 is supplied to the display element driving circuit 114, and the display element driving circuit 114 drives the display element 112 according to the image data.

  The rotation control unit 103 issues an instruction to the rotation driving unit 105 in accordance with, for example, a user operation on the operation unit 14. Rotation drive unit 105 further includes photo interrupters 51a and 51b. The rotation driving unit 105 controls the drum driving unit 32 according to the instruction supplied from the rotation control unit 103 to control the rotation operation of the drum unit 10 (drum 30). For example, the rotation drive unit 105 generates a drive pulse according to an instruction supplied from the rotation control unit 103 and drives the motor. The rotation control unit 103 generates an operation flag indicating whether or not the drum unit 10 is rotating based on the drive pulse generated by the rotation drive unit 105.

  On the other hand, the output of the photo interrupters 51a and 51b and the drive pulse for driving the motor are supplied from the rotation drive unit 105 to the rotation control unit 103. The rotation control unit 103 has a counter, for example, and counts the number of drive pulses. The rotation control unit 103 acquires the detection timing of the protrusion 46a based on the output of the photo interrupter 51b, and resets the number of pulses counted by the counter at the detection timing of the protrusion 46a. The rotation control unit 103 sequentially obtains the angle of the drum unit 10 (drum 30) based on the number of pulses counted by the counter. Angle information indicating the angle of the drum unit 10 is supplied to the image processing unit 100.

  The distance value output unit 101 receives the detection signal output from the distance sensor 60. The distance value output unit 101 performs distance measurement processing based on this detection signal, and derives the distance between the projection lens 12 and the projection medium. A distance value indicating the derived distance is supplied to the lens control unit 102.

  The lens control unit 102 uses the distance value supplied from the distance value output unit 101 as the first distance value, and generates a focus control signal for controlling the focus adjustment unit 1130 included in the emission optical system 113. At the same time, the lens control unit 102 uses the distance value supplied from the distance value output unit 101 as the second distance value, and controls the generation of the focus control signal.

  FIG. 6 shows an exemplary configuration of the lens control unit 102. The lens control unit 102 includes a determination unit 1020, a register 1021, a focus control signal generation unit 1022, and a timer 1023. The timer 1023 measures time according to the control of the determination unit 1020.

The lens control unit 102, from the distance value output section 101 together with the distance value is input, the lens position information indicating the current lens position D _L from the lens driving section 1131 is input. The distance value input to the lens control unit 102 is supplied to the focus control signal generation unit 1022 via the register 1021. The focus control signal generation unit 1022 uses the supplied distance value as a first distance value for processing. Further, the distance value input to the lens control unit 102 is supplied to the determination unit 1020. The determination unit 1020 uses the supplied distance value as a second distance value for processing. The lens position information input to the lens control unit 102 is supplied to the determination unit 1020 and the focus control signal generation unit 1022. Further, the determination unit 1020 is supplied with an operation flag indicating whether or not the drum unit 10 is rotating.

  The lens control unit 102 uses the distance value supplied from the distance value output unit 101 as the first distance value, and generates a focus control signal for controlling the focus adjustment unit 1130 included in the emission optical system 113. At the same time, the lens control unit 102 uses the distance value supplied from the distance value output unit 101 as the second distance value, and controls the generation of the focus control signal.

  The focus control signal generation unit 1022 generates a focus control signal based on the lens position information and the first distance value read from the register 1021. Here, the focus adjustment control by the focus adjustment unit 1130 will be schematically described with reference to FIG. Here, it is assumed that the focus is adjusted by moving the lens 130 back and forth among the plurality of lenses included in the focus adjustment unit 1130 with respect to the projection direction. The focus adjustment may be performed by moving a plurality of lenses including the lens 130 with respect to the projection direction.

In FIG. 7, the horizontal axis indicates the position along the projection direction of the lens 130. Based on the distance value outputted from the distance value output section 101, a target position D ₀ of the lens 130 is set. The target position D ₀ is a position where the image projected from the projection lens 12 is focused on the projection medium when the lens 130 is at this position.

If the current lens position D _L of the lens 130 is different from the target position D _0, the deviation ΔD of the current lens position D _L with respect to the target position D ₀ occurs. The deviation ΔD is a value indicating the deviation of the image projected from the projection lens 12 from the in-focus state on the projection medium. That is, the smaller the absolute value of the deviation ΔD, the more in-focus state, and the larger the absolute value of the deviation ΔD, the more out of focus state. The lens control unit 102 moves the position of the lens 130 so that the deviation ΔD becomes 0 in order to focus the projected image on the projection medium.

More specifically, in the lens control unit 102, the focusing control signal generation unit 1022 sets the first target position D _{0_1} according to the first distance value read from the register 1021. Further, focus control signal generation unit 1022, a lens position information indicating the current lens position D _L of the lens 130 in the focus adjusting unit 1130 acquires from the lens driving unit 1131.

Focus control signal generation unit 1022 calculates a first target position D _{0_1} set, the first deviation [Delta] D ₁ from the current lens position D _L shown in the acquired lens position information. The focus control signal generation unit 1022 generates a drive control signal that moves the lens 130 by the deviation ΔD, and outputs the drive control signal as the focus control signal. The focus control signal is input to the emission optical system 113 and supplied to the lens driving unit 1131. The lens driving unit 1131 drives the focus adjustment unit 1130 according to the supplied focus control signal.

  As described above, the focus control signal generation unit 1022 and the lens driving unit 1131 cooperate to constitute a focus adjustment driving unit that drives the focus adjustment unit 1130.

The determination unit 1020 sets the second target position D _{0_2} according to the second distance value. The determination unit 1020 calculates a _second deviation ΔD ₂ from the second target position D _{0 — 2} and the current lens position D _L. The determination unit 1020 further receives a first value th ₁ set as the threshold th and a second value th ₂ that is larger than the first value th ₁ . The first value th ₁ and the second value th ₂ are input from the overall control unit 120, for example. Not limited to this, the first value th ₁ and the second value th ₂ may be stored in advance in a register (not shown) or the like. The determination unit 1020 also determines the second deviation ΔD ₂ obtained from the second target position D _{0 — 2} and the current lens position D _L , the operation flag, and the first value th ₁ or the second value th _2. Whether or not to update the register 1021 is determined based on the threshold value th set. Then, the determination unit 1020 generates a register control signal for controlling the update of the register 1021 according to the determination result. That is, the determination unit 1020 functions as a control unit that controls whether or not the register 1021 is updated. The determination process in the determination unit 1020 will be described later.

  The overall control unit 120 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and uses a RAM as a work memory according to a program stored in the ROM in advance, Various processes of the projector apparatus 1 such as projection, change of the projection angle, and image cropping are controlled in an integrated manner. That is, the overall control unit 120 exchanges commands and data with the image processing unit 100, the distance value output unit 101, the lens control unit 102, the rotation control unit 103, and the operation unit 14 through a path (not shown). Can do.

  For example, the overall control unit 120 controls each unit of the projector device 1 according to a program based on a control signal supplied from the operation unit 14 in response to a user operation. Thereby, operation | movement of the projector apparatus 1 according to user operation is attained. For example, the overall control unit 120 controls each unit of the projector device 1 according to a script input from a data input unit (not shown). Thereby, the automatic control of the operation of the projector device 1 can be performed.

  Although the image processing unit 100, the distance value output unit 101, the lens control unit 102, and the rotation control unit 103 have been described as being configured by different hardware, the present invention is not limited to this example. For example, all or part of the image processing unit 100, the distance value output unit 101, the lens control unit 102, and the rotation control unit 103 may be realized as a function of the overall control unit 120 by a program module that operates on the CPU. Good.

<Focus Adjustment Processing According to Embodiment>
Next, the focus adjustment process according to the embodiment will be described. In the case where the position of the lens 130 is controlled so that the deviation ΔD becomes zero as described with reference to FIG. 7, the control is performed so that the absolute value of the deviation ΔD is equal to or less than a preset threshold th. In the embodiment, a first value th ₁ and a second value th ₂ greater than the first value th ₁ are prepared, and the first value th ₁ and the second value th ₂ are set according to conditions. Any one of them is set as a threshold th for the absolute value of the deviation ΔD.

FIG. 8 is a flowchart illustrating an example of a method for controlling the register 1021 by the determination unit 1020. Prior to the execution of the flowchart of FIG. 8, the determination unit 1020 sets the first value th ₁ as the initial value of the threshold th. Also, the determination unit 1020 illustrated in FIG. 6 resets the elapsed time measured by the timer 1023 to zero.

In step S100, the determination unit 1020 determines whether the current threshold th for the absolute value of the second deviation ΔD ₂ is the first value th ₁ or the second value th ₂ . Determining unit 1020, if the current threshold value th is determined to be a first value th _1, the process control proceeds to step S101, the absolute value of the second deviation [Delta] D ₂ is the first value th less than ₁ It is determined whether or not. If the determination unit 1020 determines that the absolute value of the _second deviation ΔD ₂ is greater than or equal to the first value th ₁ , the determination unit 1020 shifts the process to step S106 and resets the elapsed time measured by the timer 1023 to 0. Then, the process returns to step S100.

If the determination unit 1020 determines in step S101 that the absolute value of the _second deviation ΔD ₂ is less than the first value th ₁ , the determination unit 1020 shifts the process to step S102 and updates the elapsed time. Then, the determination unit 1020 determines whether or not the elapsed time has exceeded a preset time in the next step S103. When it determines with not having exceeded, the determination part 1020 returns a process to step S100.

If the determination unit 1020 determines in step S103 that the elapsed time has exceeded a preset time, the determination unit 1020 shifts the process to step S104, and sets the _second value th ₂ as the current threshold th. In step S <b> 105, the determination unit 1020 generates a register control signal that stops updating the register 1021 and supplies the register control signal to the register 1021. By this register control signal, updating of the stored contents in the register 1021 is stopped, and the distance value (first distance value) used by the focus control signal generation unit 1022 to calculate the first deviation ΔD ₁ is the register 1021. The distance value output from the distance value output unit 101 immediately before the update is stopped is fixed. Then, the process returns to step S100.

That is, in step S103, when the elapsed time exceeds the preset time while maintaining the absolute value of the _second deviation ΔD ₂ less than the _first value th ₁ , the focus position is determined in advance. It can be assumed that the time has not changed. In this case, it can be estimated that the relationship between the projection lens 12 and the projection medium is fixed. Therefore, by fixing the first distance value used by the focus control signal generation unit 1022 to generate the focus control signal, the influence on the focus adjustment due to the fluctuation of the detection signal output from the distance sensor 60 can be reduced. This can be eliminated, and the continuous minute fluctuation of the focus adjustment unit 1130 is suppressed.

In the processing up to step S104, the determination unit 1020 calculates the second deviation ΔD ₂ calculated from the second distance value and the current lens position D _L, and the in-focus positive signal generation unit 1022 sets the first distance value and the first deviation [Delta] D ₁ calculated from the current lens position D _L, due to the use of each distance value supplied from the distance value output section 101, the same value. When the update of the distance value in the register 1021 is stopped in step S105, the focusing control signal generation unit 1022 calculates the first deviation ΔD ₁ based on the distance value supplied before the update of the register 1021 is stopped. To do. In this case, since the distance value supplied to the focus control signal generation unit 1022 is not changed and is a fixed value, the first deviation ΔD ₁ does not change. On the other hand, the determination unit 1020 calculates the _second deviation ΔD ₂ according to the change in the distance value directly supplied from the distance value output unit 101. For this reason, the second deviation ΔD ₂ also changes after step S105.

In step S100, the determination unit 1020, if the current threshold value th is determined to be the second value th _2, the process proceeds to step S110. In step S110, the determination unit 1020 determines whether the operation flag indicating whether or not the drum unit 10 is rotating is ON, that is, whether or not the drum unit 10 is rotating. The determination unit 1020 can acquire the operation flag based on, for example, a motor driving pulse supplied from the rotation driving unit 105 to the rotation control unit 103.

  If the determination unit 1020 determines in step S110 that the in-operation flag is OFF (ie, the drum unit 10 is not rotating), the process returns to step S100.

If the determination unit 1020 determines in step S110 that the in-operation flag is ON, the determination unit 1020 shifts the process to step S111 and determines whether the absolute value of the second deviation ΔD ₂ is less than the second value th _2. Determine whether. If the determination unit 1020 determines that the absolute value of the second deviation ΔD ₂ is less than the second value th ₂ , the process returns to step S100.

If the determination unit 1020 determines that the absolute value of the second deviation ΔD ₂ is greater than or equal to the second value th ₁ in step S111, the determination unit 1020 shifts the process to step S112 and sets the elapsed time measured by the timer 1023. Reset to zero.

Then, in the next step S113, the determination unit 1020 sets the first value th ₁ as the current threshold th, and shifts the processing to step S114. In step S <b> 114, the determination unit 1020 generates a register control signal for restarting the update of the register 1021 and supplies the register control signal to the register 1021. As a result, the fixation of the first distance value used for calculating the first deviation ΔD ₁ by the focus control signal generation unit 1022 performed in step S105 described above is released. In other words, the distance value supplied from the distance value output unit 101 to the register 1021 is supplied again to the focus control signal generation unit 1022 and is used for calculating the first deviation ΔD ₁ as the first distance value. Therefore, the first deviation ΔD ₁ calculated by the focus control signal generation unit 1022 is updated according to the distance value output from the distance value output unit 101. When the determination unit 1020 restarts the update of the register 1021 and releases the fixation of the second distance value held in the register 1021, the process returns to step S100. As a result, the focus adjustment at the _first value th ₁ after step S101 is resumed.

After step S110, the processing from step S111 relates to the focus adjustment processing during rotation of the drum unit 10. That is, during the rotation of the drum unit 10, the projection direction by the projection lens 12 changes according to the rotation of the drum unit 10, and the distance between the projection lens 12 and the projection medium also changes with this change. It is always necessary to monitor the focus. Therefore, when the absolute value of the second deviation ΔD ₂ becomes equal to or greater than the second value th ₂ in step S111, the threshold value th for the absolute value of the second deviation ΔD ₂ is set to the first value th ₁ of the initial value. The distance value supplied to the focus control signal generation unit 1022 is released, and normal focus adjustment is performed.

On the other hand, when the rotation of the drum unit 10 is minute and the absolute value of the second deviation ΔD ₂ is less than the second value th ₂ , the first distance used by the focus control signal generation unit 1022 is used. The value remains fixed. Therefore, there is no change in the first deviation ΔD ₁ calculated by the focus control signal generation unit 1022, and useless movement of the focus adjustment unit 1130 is suppressed.

<Another example of register control method by determination unit>
Next, another example of a method for controlling the register 1021 by the determination unit 1020 according to the embodiment will be described. In addition, in this other example, since each structure demonstrated using FIGS. 1-7 is applicable as it is, detailed description here is abbreviate | omitted. FIG. 9 is a flowchart illustrating another example of a method for controlling the register 1021 by the determination unit 1020.

In step S200, the determination unit 1020 determines whether or not the operation flag indicating whether or not the drum unit 10 is rotating is ON (on), that is, whether or not the drum unit 10 is rotating. judge. If the determination unit 1020 determines in step S200 that the in-operation flag is ON, the determination unit 1020 shifts the process to step S201 and determines whether or not the absolute value of the _second deviation ΔD ₂ is less than the first value th _1. Determine whether. If the determination unit 1020 determines that the absolute value of the _second deviation ΔD ₂ is less than the first value th ₁ , the process proceeds to step S203.

In step S <b> 203, the determination unit 1020 generates a register control signal for stopping the update of the register 1021 and supplies the register control signal to the register 1021. This register control signal stops the update of the stored contents in the register 1021, and the first distance value used by the focus control signal generation unit 1022 to calculate the first deviation ΔD ₁ is the update of the register 1021. The distance value output from the distance value output unit 101 immediately before the operation is fixed. Then, the process returns to step S200.

  In step S203, if the update of the register 1021 has already been stopped, the state is maintained and the stored contents of the register 1021 are held as they are.

Determining unit 1020, at step S201, if the absolute value of the second deviation [Delta] D ₂ is determined to be the first value th ₁ or more, the process proceeds to step S202. In step S <b> 202, the determination unit 1020 generates a register control signal for restarting the update of the register 1021 and supplies the register control signal to the register 1021. As a result, the fixation of the first distance value used for calculating the first deviation ΔD ₁ by the focusing control signal generation unit 1022 performed in step S203 described above is released. Then, the process returns to step S200.

On the other hand, if the determination unit 1020 determines that the in-operation flag is OFF in step S200 described above, the determination unit 1020 shifts the process to step S204. In step S204, the determination unit 1020 determines whether or not the absolute value of the second deviation ΔD ₂ is less than the second value th ₂ . If the determination unit 1020 determines that the absolute value of the second deviation ΔD ₂ is greater than or equal to the second value th ₂ , the determination unit 1020 shifts the process to step S202 described above and releases the first distance value from being fixed.

If the determination unit 1020 determines that the absolute value of the second deviation ΔD ₂ is less than the second value th ₂ in step S204, the determination unit 1020 shifts the process to step S203 described above, and sets the first distance value. To fix. Then, the process returns to step S200.

Thus, in this other example as well, as in the example described with reference to FIG. 8, even when the drum unit 10 is rotating, the rotation of the drum unit 10 is very small and the second deviation ΔD _2. Is within the first value th ₁ , the first distance value used by the focus control signal generation unit 1022 remains fixed. Therefore, there is no change in the first deviation ΔD ₁ calculated by the focus control signal generation unit 1022, and useless movement of the focus adjustment unit 1130 is suppressed. Further, according to the flowchart of FIG. 9, this control can be realized with fewer steps than the processing according to the flowchart of FIG. 8.

  As described above, according to the embodiment, the focus adjustment unit 1130 is appropriately controlled according to the variation in the distance between the projection lens 12 and the projection medium, the presence / absence of the rotation of the drum unit 10, and the size thereof. Therefore, wear and fatigue of the mechanical part in the focus adjustment unit 1130 are suppressed, and a situation in which the projected image projected on the projection medium becomes visually unpleasant is prevented.

<Modification of Embodiment>
In the above description, the value indicating the deviation from the focused state of the image projected from the projection lens 12 on the projection medium is obtained based on the distance between the projection lens 12 and the projection medium. It is not limited to this example, You may obtain | require the value which shows the shift | offset | difference of focusing with another method. For example, the degree of focusing may be obtained based on an image projected on the projection medium. In this case, the distance sensor 60 is replaced with an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) imager, and the distance value output unit 101 is replaced with an analysis unit. The lens control unit 102 obtains a value indicating a deviation from the in-focus state based on the analysis result of the captured image by the analysis unit. For example, the lens control unit 102 obtains the deviation from the in-focus state based on the contrast of the image, or the method for obtaining the deviation from the in-focus state based on the phase difference of the light incident on the image sensor divided into two. Can be used.

DESCRIPTION OF SYMBOLS 1 Projector apparatus 10 Drum part 12 Projection lens 14 Operation part 20 Base 30 Drum 32 Drum drive part 60 Distance sensor 100 Image processing part 101 Distance measuring part 102 Lens control part 103 Rotation control part 105 Rotation drive part 110 Optical engine part 112 Display Element 113 Emission optical system 120 Overall control unit 1130 Focus adjustment unit 1131 Lens drive unit

Claims (3)

A distance value output unit that outputs a distance value indicating the measured distance from the projection unit to the projection medium;
A focus adjustment unit that adjusts the focus of light passing through the projection unit;
Using the distance value as a first distance value, detecting a first deviation from a focused state of the light projected on the projection medium by the projection unit based on the first distance value, A focus adjustment drive unit that drives the focus adjustment unit so that a value indicating a deviation of 1 becomes 0;
Whether the distance value is used as a second distance value, a second deviation from the focused state of the light is detected based on the second distance value, and the value indicating the second deviation is less than a threshold value A determination unit for determining whether or not,
When the determination unit determines that the state in which the threshold value is the first value and the value indicating the second deviation is less than the first value has continued for a predetermined time or longer , the threshold value is set. set the first value is greater than the second value, and stops updating of the first distance value,
The determination unit determines that the threshold value is the second value, the projection direction is being changed by the projection unit, and the value indicating the second deviation is equal to or greater than the second value. when, sets the threshold value to said first value, the focus adjusting apparatus characterized by a control unit to restart the updating of the first distance value. A projection unit for projecting light;
A change unit for changing the projection direction of the projection unit;
A light modulator that modulates and emits light according to an image;
A focus adjustment unit that adjusts the focus of light emitted from the light modulation unit and supplies the light to the projection unit;
A distance value output unit that outputs a distance value indicating the measured distance from the projection unit to the projection medium;
Using the distance value as a first distance value, detecting a first deviation from a focused state of the light projected on the projection medium by the projection unit based on the first distance value, A focus adjustment drive unit that drives the focus adjustment unit so that a value indicating a deviation of 1 becomes 0;
Whether the distance value is used as a second distance value, a second deviation from the focused state of the light is detected based on the second distance value, and the value indicating the second deviation is less than a threshold value A determination unit for determining whether or not,
When the determination unit determines that the state in which the threshold value is the first value and the value indicating the second deviation is less than the first value has continued for a predetermined time or longer , the threshold value is set. Set a second value greater than the first value, and stop updating the first distance value ;
The determination unit determines that the threshold value is the second value, the changing unit is changing the projection direction, and the value indicating the second deviation is equal to or greater than the second value. when it is determined to set the threshold value to said first value, the projection apparatus characterized by a control unit to restart the updating of the first distance value. A change step for changing the projection direction of the light projected from the projection unit;
A distance measuring step for measuring a distance from the projection unit to the projection medium and outputting a distance value;
The projection unit uses the distance value as a first distance value, detects a first deviation from a focused state of light projected onto the projection medium by the projection unit based on the first distance value, and the projection unit. A focus adjustment step of adjusting the focus of the light passing through the lens so that the value indicating the first deviation becomes 0;
Whether the distance value is used as a second distance value, a second deviation from the focused state of the light is detected based on the second distance value, and the value indicating the second deviation is less than a threshold value A first determination step for determining whether or not;
A second determination step of determining whether or not the state in which the value indicating the second deviation is less than the threshold value continues for a predetermined time;
The threshold value is a first value, the first determination step determines that the value indicating the second deviation is less than the first value, and the second determination step determines the second value. A first value that sets the threshold value to a second value that is greater than the first value when it is determined that a state in which the value indicating the deviation is less than the first value has continued for a predetermined time or longer. A threshold change step;
The threshold value is the first value, the first determination step determines that the value indicating the second deviation is less than the first value, and the second determination step determines the first value. When it is determined that the state in which the value indicating the deviation of 2 is less than the first value has continued for a predetermined time or longer, the updating of the first distance value used in the focus adjustment step is stopped. 1 control step;
The threshold value is the second value, and the first determination step determines that the value indicating the second deviation is equal to or greater than the second value, and the projection direction is being changed in the change step. A second threshold value changing step for setting the threshold value from the second value to the first value;
The threshold value is the second value, and the first determination step determines that the value indicating the second deviation is equal to or greater than the second value, and the projection direction is being changed in the change step. And a second control step of resuming the update of the first distance value that has been stopped in the first control step.

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