JP2006047334A - Projector apparatus and zooming control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a projector apparatus capable of automatically changing the setting of zooming magnification etc., to the appropriate one in accordance with a change of a projection environment. <P>SOLUTION: The projector apparatus is provided with an area sensor 21 for detecting the quantity of display light reflected from an image part on a screen surface projected by a projection optical system 30 and the quantity of environmental light reflected from parts other than the image part on the screen surface, and the zooming magnification of the projection optical system 30 is varied so that a contrast value, that is, a ratio of the detected display light quantity to the detected environmental light quantity may be within a prescribed extent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector device and a zoom control method.

In the conventional projector device, the contrast of the projection image is directly affected by the brightness of the projection environment. Therefore, when the surroundings of the screen become bright, the contrast of the projection image is lowered and it becomes difficult to see. For this reason, the user raises the contrast by appropriately changing the zoom magnification of the projector device to reduce the projected image to a small screen. And the projector apparatus provided with the electric zoom is known (for example, refer patent document 1, 2). In addition to the zoom magnification, there are other adjustment items that affect the image, such as the lamp light amount and the aperture, and it is necessary to adjust them appropriately. As a conventional technique for easily setting these adjustment items, there is known a so-called “lens memory function” provided in a projector apparatus for digital cinema manufactured by NEC View Technology. This “lens memory function” adjusts the lens status of lens shift, zoom, and focus in advance according to the video input signal, so that the lens status can be adjusted according to various video sources (screen aspect, resolution, etc.). Switch instantly.
JP 2002-131604 A JP 2001-194572 A

  However, in the projector apparatus provided with the above-described conventional electric zoom, the user adjusts the zoom magnification appropriately by operating the remote controller or the like according to the change of the projection environment, so that the work load is large. Further, since the adjustment is individually made together with the zoom magnification and other adjustment items such as the lamp light quantity and the aperture, it takes time to make the adjustment. Also, it is inconvenient and very difficult to operate the remote control in a relatively dark environment. In the “lens memory function” described above, since it is necessary to register the setting contents for each adjustment item in advance for each image to be projected, the setting is not always appropriate for a change in the actual projection environment. It is not suitable for the purpose of responding to changes in the projection environment.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a projector apparatus and a zoom control method capable of automatically changing a zoom magnification and the like to an appropriate setting in accordance with a change in projection environment. Is to provide.

  In order to solve the above-described problems, a projector device according to the present invention includes a light source unit that emits illumination light in a projector device that projects an image according to input image information onto a screen, and the light source unit includes: Spatial modulation means for modulating the emitted illumination light according to input image information to generate projection light, projection optical means for projecting projection light generated by the spatial modulation means, and projection optical means for projection A light amount detection means for detecting a display light amount reflected from an image portion on the screen surface and an environmental light amount reflected from a portion other than the image on the screen surface, and a zoom magnification at which the projection optical means projects an image. Zoom variation means for varying the zoom variation means, and the zoom variation means has a predetermined contrast range that is a ratio of the display light amount detected by the light amount detection means and the environmental light amount. As a value, and wherein varying the zoom magnification of the projection optical unit.

  In the projector device according to the present invention, the zoom variation means varies the zoom magnification in the reduction direction when the ambient light becomes bright or the projection light becomes dark.

  In the projector device according to the present invention, the zoom variation means varies the zoom magnification in the enlargement direction when the ambient light becomes dark or when the projection light becomes bright.

  In the projector device according to the present invention, the light amount detecting means is an area sensor, and the zoom varying means detects at least a boundary portion of the projected image by the area sensor and detects contrast.

  In the projector device according to the present invention, the projector further includes a calibration switch that allows an operator to instruct the start of the operation of the zoom variation unit, and the zoom variation unit includes the calibration switch after the calibration switch is pressed. The zoom magnification of the projection optical means is varied.

  In the projector apparatus according to the present invention, a diaphragm control unit capable of limiting a light beam of projection light projected by the projection optical unit, a light amount control unit capable of controlling a light amount of illumination light emitted from the light source unit, and the light amount The zoom variation unit, the aperture control unit, and the light source control unit are operated in cooperation so that a contrast value, which is a ratio between the display light amount detected by the detection unit and the environmental light amount, is a value within a predetermined range. And a control means.

  A zoom control method according to the present invention is a zoom control method according to calibration in the projector device according to claim 1, wherein the first step of turning off the light source means and the state where the light source means is turned off. The second step of measuring the first light amount reflected from the screen surface by the light amount detecting means, the third step of turning on the light source means, and the projection optical means projecting with the light source means turned on The fourth step of measuring the second light quantity reflected from the image portion on the screen surface by the light quantity detection means and the contrast value is obtained from the ratio between the detected first light quantity and the second light quantity. 5 and the contrast optical value obtained in the fifth step is smaller than a value within a predetermined range, the projection optical means is controlled by the zoom changing means. When the zoom magnification is changed in the reduction direction and the contrast value obtained in the fifth step is larger than a value within a predetermined range, the zoom change means increases the zoom magnification of the projection optical means. And a sixth step of varying.

  In the zoom control method according to the present invention, the first to sixth steps operate after the projector device is turned on.

  In the zoom control method according to the present invention, the value within the predetermined range is a contrast value obtained in the fifth step after power-on.

  In the zoom control method according to the present invention, the first to sixth steps operate after the calibration switch is turned on.

  In the zoom control method according to the present invention, the first to sixth steps are performed until a contrast value, which is a ratio between the display light amount detected by the light amount detection means and the environmental light amount, is equal to a value within a predetermined range. It is characterized by repetition.

  A zoom control method according to the present invention is a zoom control method according to calibration in the projector device according to claim 6, wherein the zoom fluctuation unit is operated so that the contrast value is within a predetermined range. And a second step of operating the aperture control means so that the contrast value falls within a predetermined range when the contrast value does not fall within a predetermined range in the first step; A third step of operating the light source control means so that the contrast value falls within a predetermined range when the contrast value does not fall within the predetermined range even in the second step. It is said.

  According to the present invention, the zoom magnification or the like can be automatically changed to an appropriate setting in accordance with a change in the projection environment. This reduces the burden on the user.

  Further, since the zoom magnification, the illumination light quantity, and the projection system aperture are changed in conjunction with each other, the contrast can be adjusted efficiently.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of an optical system of a projector system according to an embodiment of the present invention. The projector apparatus 1 is a color-sequential display type projector, and includes a single-plate type optical system using a transmissive LCD as a light modulation element.
In FIG. 1, the projector device 1 includes an illumination optical system 10 and a projection optical system 30. In the illumination optical system 10, the lamp 11 is a white light source including R, G, and B wavelength components. The luminous flux generated by the lamp 11 is transmitted to the color wheel 14 through the condenser lens 13 after changing the direction of the optical path after the infrared component is removed by the IR cut mirror 12. Next, spectral processing is performed in a time-sharing manner in synchronization with an image frame by a color filter provided in the color wheel 14.

  The light of each of the red, blue, and green frames spectrally processed by the color wheel 14 is diffused through the integrator rod 15 and the relay lens 16 to remove surface unevenness, and then the light is emitted by the illumination system diaphragm 17. The angle is constrained. The light that has passed through the illumination system diaphragm 17 is polarized by the polarization conversion element 18 and then reaches the transmissive LCD 19 that is a light modulation element. The transmissive LCD 19 controls the brightness of transmitted light by modulating the transmittance in units of pixels. The light transmitted through the transmissive LCD 19 is reflected by the total reflection mirror 20 a or the half mirror 20 b provided in the mirror unit 20 and emitted to the projection optical system 30. An area sensor 21 for detecting the amount of reflected light is provided in the direction opposite to the projection direction with the mirror unit 20 as a boundary.

  In the projection optical system 30, the light incident from the illumination optical system 10 passes through a projection lens group having a zoom lens 32 and a focus lens 33 and is imaged on the screen 41. In the projection lens group, the zoom magnification is adjusted and the focus position is adjusted by adjusting each lens position. In addition, a projection system diaphragm 31 is provided to adjust the amount of projection light and to reduce the flare caused by stray light by restricting the ray angle.

  In the mirror unit 20, the total reflection mirror 20a and the half mirror 20b are provided adjacent to each other, and a sliding operation is possible so that either the total reflection mirror 20a or the half mirror 20b is disposed on the optical path. Yes. When the total reflection mirror 20a is inserted on the optical path, it is a normal projection state in which all illumination light from the transmissive LCD 19 is projected. On the other hand, when the half mirror 20b is inserted on the optical path, almost half of the illumination light from the transmissive LCD 19 is projected and from the surface of the screen 41 returning through the projection lens group. Nearly half of the reflected light forms an image on the area sensor 21. The area sensor 21 detects the amount of light reached.

  The distance between the area sensor 21 and the mirror unit 20 is equal to that between the transmissive LCD 19 and the mirror unit 20. Thereby, the reflected light from the screen 41 returning via the projection lens group can be imaged on the area sensor 21.

FIG. 2 is a block diagram showing an electrical configuration of the projector apparatus 1 described above.
In FIG. 2, a system control microcomputer 101 (hereinafter, control unit 101) controls each unit in the projector device 1. The AC power input unit 102 inputs AC power from a commercial power source. This AC power is boosted by the booster circuit 103 and then supplied to the constant current drive circuit 104. The constant current drive circuit 104 supplies a drive current to the lamp 11 and controls a drive current supplied to the lamp 11 based on a control signal from the control unit 101. The lamp 11 generates a light amount corresponding to the drive current.

  The color wheel drive mechanism 105 includes a motor that rotationally drives the color wheel 14 and performs drive control of the color wheel 14 based on a control signal from the control unit 101. The color wheel filter phase detection mechanism 106 includes a sensor that detects the phase of the color filter provided in the color wheel 14, and outputs a sensor output signal to the control unit 101. The control unit 101 detects the phase of the color filter based on the sensor output signal. R, G, and B phases in the illumination light are detected based on the phase of the color filter.

  The illumination system diaphragm drive mechanism 107 includes a motor that drives the illumination system diaphragm 17 to open and close, and performs drive control of the illumination system diaphragm 17 based on a control signal from the control unit 101. The illumination system aperture opening amount detection mechanism 108 includes a sensor that detects the aperture amount of the illumination system aperture 17, and outputs a sensor output signal to the control unit 101. The control unit 101 detects the opening amount of the illumination system diaphragm 17 based on the sensor output signal. The amount of illumination light varies according to the opening amount of the illumination system diaphragm 17.

  The mirror drive mechanism 109 has a motor that slides the mirror unit 20, and performs drive control of the mirror unit 20 based on a control signal from the control unit 101. The mirror slide position detection mechanism 110 has a sensor that detects the slide position of the mirror unit 20, and outputs a sensor output signal to the control unit 101. Based on the sensor output signal, the control unit 101 detects which of the total reflection mirror 20a and the half mirror 20b is inserted on the optical path.

  The projection system diaphragm drive mechanism 111 has a motor that drives the projection system diaphragm 31 to open and close, and performs drive control of the projection system diaphragm 31 based on a control signal from the control unit 101. The projection system diaphragm opening amount detection mechanism 112 includes a sensor that detects the opening amount of the projection system diaphragm 31, and outputs a sensor output signal to the control unit 101. The control unit 101 detects the opening amount of the projection system diaphragm 31 based on the sensor output signal. The amount of projection light varies and the ray angle of projection light is constrained according to the opening amount of the projection system diaphragm 31.

  The zoom lens drive mechanism 113 has a motor that slides the zoom lens 32 and performs drive control of the zoom lens 32 based on a control signal from the control unit 101. The zoom lens position detection mechanism 114 includes a sensor that detects the position of the zoom lens 32, and outputs a sensor output signal to the control unit 101. The control unit 101 detects the zoom magnification based on the sensor output signal. The zoom magnification varies depending on the position of the zoom lens 32.

  The focus lens drive mechanism 115 includes a motor that slides the focus lens 33, and performs drive control of the focus lens 33 based on a control signal from the control unit 101. The focus lens position detection mechanism 116 includes a sensor that detects the position of the focus lens 33, and outputs a sensor output signal to the control unit 101. The controller 101 detects the in-focus position based on the sensor output signal. The focus position varies depending on the position of the focus lens 33.

The area sensor (projection screen light amount detection mechanism) 21 has a sensor for detecting the light amount, and outputs a sensor output signal to the control unit 101. The control unit 101 detects the amount of reflected light from the surface of the screen 41 based on the sensor output signal.
The environmental light amount detection mechanism 120 has a sensor for detecting the light amount, and outputs a sensor output signal to the control unit 101. The ambient light quantity detection mechanism 120 is for detecting the light quantity around the projector system. The control unit 101 detects the amount of ambient light based on the sensor output signal. In the present embodiment, the area sensor 21 serves as both the projection screen light amount detection mechanism and the environment light amount detection mechanism 120.

FIG. 3 is an explanatory diagram for explaining light amount detection by the area sensor 21. As shown in FIG. 3, on the surface of the screen 41, a screen projection portion irradiated with projection light from the projector device 1 and a screen non-projection portion outside the illumination projection field angle of the projector device 1 are included. It is. The area sensor 21 includes a range for detecting the amount of reflected light from the screen projection portion (display light amount level detection range), a range for detecting the amount of reflected light from the non-projected portion of the screen (environment light amount level detection range), Have Therefore, according to this area sensor 21, the amount of reflected light from the screen projection portion (display light amount) and the amount of reflected light from the non-projection portion of the screen (environment light amount) are detected simultaneously in one measurement. be able to. The amount of display light is the amount of reflected light due to projection light and ambient light, and is expressed by equation (1).
Display light quantity = Projection light quantity + Ambient light quantity (1)

  The area sensor 21 detects the amount of light in pixel units. The control unit 101 calculates the display light amount by averaging the light amount detection values of the pixels in the display light amount level detection range. Similarly, the ambient light amount is calculated by averaging the light amount detection values of the pixels in the ambient light level detection range.

  The calibration switch 130 is a switch for instructing execution of calibration of the projector system, and is operated by the user. This switch signal is output to the control unit 101.

  4 to 7 are diagrams for explaining the level of reflection luminance on the screen 41. FIG. In FIG. 4, the brightness level of the reflected light by the light projected from the projector device 1 in the dark is shown in association with the display position on the screen 41. In FIG. 5, the brightness level of the reflected light by the ambient light when the surroundings are bright and nothing is projected from the projector device 1 is shown in association with the display position on the screen 41. As shown in FIG. 5, when the surroundings are bright and the ambient light reaches the screen 41, a black floating phenomenon in which the black level floats occurs.

  Next, in FIG. 6, the brightness level of the reflected light by the light projected from the projector device 1 in the bright surroundings is shown in association with the display position on the screen 41. As shown in FIG. 6, the reflection luminance level is obtained by adding the reflection luminance of the dark projection image of FIG. 4 to the black level floating caused by the ambient light shown in FIG. In this state, the reflected brightness of the white part of the projected image increases due to black floating, but the reflected brightness of the black part of the projected image also increases, so the ratio between the reflected brightness of the white part and the reflected brightness of the black part means contrast. As a result.

  In FIG. 7, the brightness level of the reflected light by the light projected by reducing the projection image shown in FIG. 6 by changing the zoom magnification is shown in association with the display position on the screen 41. As shown in FIG. 7, the level of black floating due to ambient light does not change, but the reflection luminance level of the white portion of the projected image increases due to the light condensing effect by the reduction zoom, so the contrast becomes higher than the state of FIG. 6. . Thereby, the projected image becomes small, but it becomes easier to see than the state of FIG. 6 due to the increase in contrast.

Next, an operation related to the contrast correction of the projector device 1 described above will be described.
FIG. 8 is a main flowchart of a contrast correction sequence performed by the control unit 101 of the projector device 1 according to this embodiment.
In FIG. 8, the control unit 101 determines whether or not the start conditions of the contrast correction sequence are met (step S101). The activation condition of the contrast correction sequence differs depending on whether the activation mode selected in advance by the user is the automatic mode or the manual mode. When the automatic mode is selected, the control unit 101 detects the ambient light amount when the projector apparatus 1 is turned on, when the video input source is changed, or at a certain time interval, and remarkably from the previous detected light amount. When changed, the contrast correction sequence is started. On the other hand, when the manual mode is selected, the control unit 101 starts the contrast correction sequence when the calibration switch 130 is pressed by the user.

  If the start conditions of the contrast correction sequence do not match, the total reflection mirror 20a is slid so as to be inserted into the optical path, and the process is terminated (step S102).

  If the start conditions of the contrast correction sequence are met, the control unit 101 starts the contrast correction sequence (step S103). Next, the control unit 101 performs initial setting (step S104). In this initial setting, the reference values related to the lamp light quantity and the illumination system diaphragm are based on the image tone mode (living mode; brightness priority, cinema mode; black float prevention priority) that is selectively set by the user in advance. Is set. Specifically, at the time of starting the contrast correction sequence, when priority is given to brightness, each control value is set to increase the lamp light amount and open the illumination system diaphragm. On the other hand, when priority is given to prevention of black floating, each control value is set so as to reduce the lamp light amount and narrow down the illumination system diaphragm. The control values at the start of the contrast correction sequence are set as the reference values for the lamp light quantity and the illumination system diaphragm.

  Further, the projection system aperture 31 is initialized so that the area sensor 21 can detect the reflected luminance from the screen 41 via the projection optical system 30. As this initial value, a final set value at the time of previous use, for example, a value corresponding to a mode relating to an image tone or a value set by the user's intention is used. The zoom magnification and the focus control value are based on values set at the time of starting the contrast correction sequence, specifically, set values in a dark state set by the user.

  Next, the control unit 101 outputs a control signal to the mirror drive mechanism 109, and inserts the half mirror 20b on the optical path (step S105).

  Next, the control unit 101 activates the contrast measurement sequence shown in FIG. 9 (step S106).

  In FIG. 9, the control unit 101 first stores the current control value of the illumination system diaphragm 17 in a memory (step S201). The stored control value is used when returning to the current state. Next, the illumination system diaphragm 17 is driven to be fully closed (step S202). In this state, the illumination light is shielded, and no light is projected from the projector device 1.

  Next, the control unit 101 performs a projection screen light amount detection process shown in FIG. 10 for the non-display unit (step S203). In the processing of FIG. 10, the phase of the color filter provided in the color wheel 14 is detected by the color wheel filter phase detection mechanism 106, thereby detecting the R, G, and B phases in the illumination light. Based on this phase detection signal, the output from the area sensor 21 is captured, and the amount of reflected light from the surface of the screen 41 is detected for each of the R, G, and B phases. First, when the R phase is detected (step S301), the R light quantity is detected (step S302). Next, when the G phase is detected (step S303), the amount of G light is detected (step S304). Next, when the B phase is detected (step S305), the B light amount is detected (step S306). Next, a luminance signal value is calculated from the detected R, G, and B light amounts (step S307). This luminance signal value corresponds to the amount of environmental light.

  Returning to FIG. 9, the control unit 101 stores the luminance signal value in the memory as an environmental light quantity measurement value (step S204). Next, the control value of the illumination system diaphragm 17 stored in step S201 is read from the memory, and the state of the illumination system diaphragm 17 is returned to the previous state based on the read control value (step S205).

  Next, the control unit 101 performs a projection screen light amount detection process for the display unit (step S206). In this processing, the transmissive LCD 19 is driven and controlled so that uniform white color is displayed on the surface of the screen 41. Then, the luminance signal value is calculated by the processing shown in FIG. This luminance signal value corresponds to the amount of display light. Next, the control unit 101 stores the luminance signal value in the memory as a display light quantity measurement value (step S207).

Returning to FIG. 8, the control unit 101 performs the contrast value calculation processing shown in FIG. 11 (step S107). In the process of FIG. 11, first, the ambient light quantity measurement value and the display light quantity measurement value are read from the memory (steps S401 and S402). Next, a contrast value is calculated by the equation (2) (step S403).
Contrast calculation value C = Display light quantity measurement value / Environment light quantity measurement value (2)

  Returning to FIG. 8, the control unit 101 determines whether or not the calculated contrast value is within the target allowable range (step S108). As a result of this determination, if it is within the target allowable range, the process proceeds to step S102, where the total reflection mirror 20a is slid so as to be inserted into the optical path, and the process is terminated. On the other hand, if it is not within the target allowable range, the contrast adjustment control sequence shown in FIG. 12 is started (step S109).

  In FIG. 12, the control unit 101 first determines whether or not the contrast calculation value is larger than the target allowable maximum value (step S501). As a result of this determination, if it is larger than the target allowable maximum value, the contrast down adjustment control sequence shown in FIG. 13 is started (step S502), and adjustment for reducing the contrast is performed.

  In FIG. 13, in the contrast reduction adjustment control sequence, the control unit 101 first determines whether or not the zoom magnification is at the enlargement limit (step S601). If the result of this determination is that the enlargement limit is not reached, the zoom lens 32 is driven one step toward the enlargement of the zoom magnification (step S602). As a result, the zoom magnification is increased by one step, and the projection light is darkened accordingly, so that the contrast is lowered.

  On the other hand, when the zoom magnification is the enlargement limit, it is determined whether or not the lamp light amount is the minimum light amount (step S603). As a result of the determination, if the minimum light amount is not reached, the constant current drive circuit 104 is driven by one step so that the light emission amount of the lamp 11 decreases (step S604). As a result, the lamp light amount is reduced by one step, and the projection light is darkened accordingly, so that the contrast is lowered.

  On the other hand, if the lamp light amount is the minimum light amount, it is determined whether or not the projection system diaphragm 31 is fully stopped (step S605). If the result of this determination is that the aperture has not been cut off, the projection system aperture 31 is driven one step toward the closing side (step S606). As a result, the projection system diaphragm 31 is reduced by one step, and the projection light is darkened accordingly, so that the contrast is lowered.

  On the other hand, when the projection system diaphragm 31 is a diaphragm stop, since the contrast cannot be lowered any more, a display for notifying the user that it is out of the contrast control range is performed. For example, the display LED is turned on (step S607). Next, the total reflection mirror 20a is slid so as to be inserted into the optical path, and the process is terminated (step S608).

  After the processes in steps S602, S604, and S606, the control unit 101 returns the contrast adjustment control sequence in FIG. 12 and returns to FIG. 8 by the return process, and starts the contrast measurement sequence in step S106 to restore the contrast. Measure.

  As described above, when the calculated contrast value is larger than the target value allowable range, the contrast is measured by increasing the zoom magnification step by step until the zoom magnification reaches the enlargement limit by the contrast down adjustment control sequence of FIG. Repeatedly, the adjustment is completed when the calculated contrast value falls within the target value allowable range. However, if the calculated contrast value is still larger than the target value allowable range even when the zoom magnification is limited to the enlargement limit, the contrast measurement is repeated while decreasing the lamp light amount step by step until the lamp light amount is minimized. If the calculated value falls within the target value allowable range, the adjustment is completed. If the calculated contrast value is still larger than the target value allowable range, repeat the measurement of the contrast while stepping down the projection system aperture one step at a time until the projection system aperture is finally closed, and the calculated contrast value will be within the target value allowable range. If it falls within the range, the adjustment is completed.

  On the other hand, if it is determined in step S501 in FIG. 12 that the calculated contrast value is not greater than the target allowable maximum value (that is, the contrast calculated value is smaller than the target value allowable range), the contrast increase shown in FIG. An adjustment control sequence is activated (step S503), and adjustment for increasing the contrast is performed.

  In FIG. 14, in the contrast increase adjustment control sequence, the control unit 101 first determines whether or not the projection system aperture 31 is open (step S701). If the result of this determination is that the projection is not open, the projection system diaphragm 31 is driven one step toward the opening side (step S702). Thereby, the projection system diaphragm 31 becomes a large diaphragm by one step, and the projection light becomes brighter by that amount, so that the contrast is increased.

  On the other hand, if the projection system diaphragm 31 is open, it is determined whether or not the lamp light amount is the maximum light amount (step S703). If the maximum light quantity is not reached as a result of this determination, the constant current drive circuit 104 is driven by one step to increase the light emission amount of the lamp 11 (step S704). Thereby, the lamp light amount is increased by one step, and the projection light is brightened by that amount, so that the contrast is increased.

  On the other hand, if the lamp light amount is the maximum light amount, it is determined whether or not the zoom magnification is at the reduction limit (step S705). If the result of this determination is that the reduction limit has not been reached, the zoom lens 32 is driven one step toward the side where the zoom magnification is reduced (step S706). As a result, the zoom magnification is reduced by one step, and the projection light is brightened accordingly, so that the contrast is increased.

  On the other hand, when the zoom magnification is at the reduction limit, the contrast cannot be increased any more, so a display for notifying the user that it is out of the contrast control range is performed. For example, the display LED is turned on (step S707). Next, the total reflection mirror 20a is slid so as to be inserted into the optical path, and the process is terminated (step S708).

  After the processing in steps S702, S704, and S706, the control unit 101 returns the contrast adjustment control sequence in FIG. 12 and returns to FIG. 8 by return processing, and starts the contrast measurement sequence in step S106 to restore contrast. Measure.

  As described above, when the calculated contrast value is smaller than the target value allowable range, the contrast is measured while the projection system aperture is opened step by step until the projection system aperture is opened by the contrast up adjustment control sequence in FIG. Repeatedly, the adjustment is completed when the calculated contrast value falls within the target value allowable range. However, if the calculated contrast value is still smaller than the target value allowable range even when the projection system aperture is opened, the contrast measurement is repeated while increasing the lamp light amount step by step until the next maximum lamp light amount. If the calculated value falls within the target value allowable range, the adjustment is completed. If the calculated contrast value is still smaller than the target value tolerance, the contrast calculation is repeated while reducing the zoom magnification step by step until the zoom magnification finally reaches the reduction limit. If it falls in, the adjustment is completed.

  Next, the control unit 101 repeats the above-described contrast up / down adjustment and measurement. If the calculated contrast value falls within the target allowable range, the control unit 101 proceeds to step S102 and slides the total reflection mirror 20a so as to be inserted into the optical path. The process ends.

  Note that the target allowable range related to the contrast value may be set in the projector device 1 in advance, or after the projector device 1 is turned on, the display light amount and the environmental light amount are measured (2). It may be automatically set based on a contrast calculation value calculated by an equation.

  As described above, according to the present embodiment, the display light amount reflected from the image portion on the screen surface and the environmental light amount reflected from the portion other than the image on the screen surface are detected, and the detected display light amount and environmental light amount are detected. Adjustment is performed to decrease or increase the contrast so that the contrast value, which is the ratio between the two, becomes a value within a predetermined range. This adjustment varies the zoom magnification, the lamp light quantity, or the projection system aperture. Thereby, the zoom magnification and the like can be automatically changed to an appropriate setting in accordance with the change in the projection environment, and the burden on the user is reduced.

  In contrast adjustment, since the zoom magnification, the lamp light amount, and the projection system aperture are changed in conjunction with each other, the adjustment can be made efficiently.

  In addition to adjusting the light quantity of the illumination light source (lamp light quantity), changing the zoom magnification at the time of projection increases the brightness and contrast of the projection screen as a small screen size when the projection environment is bright, while the projection environment is When it is dark, the brightness and contrast of the projection screen can be lowered as a large screen size. As a result, the range of projection environments that can be handled is widened, and it is possible to provide an excellent projector device that can flexibly cope with large environmental changes.

  In the above-described embodiment, the contrast calculation value is represented by the ratio of the white level of the projected portion on the screen 41 and the black level of the non-projected portion as shown in the above equation (2). A black display by projection from the projector device 1 may be used as the level, and a black floating component due to flare or the like during projection may be included in the contrast calculation value.

  A photodiode or the like may be used as the projection screen light amount detection mechanism and the environmental light amount detection mechanism. In the case of a photodiode, the amount of environmental light can be measured by not projecting illumination light from the projector device 1, and the amount of display light can be measured by projecting illumination light. Further, the environmental light quantity detection mechanism may be prepared separately from the projection screen light quantity detection mechanism. If an environmental light quantity detection mechanism is separately provided, it is possible to constantly monitor environmental changes without switching projected images.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.

It is sectional drawing which shows the structure of the optical system of the projector system which concerns on one Embodiment of this invention. It is a block diagram which shows the electric constitution of the projector apparatus 1 which concerns on the same embodiment. It is explanatory drawing for demonstrating the light quantity detection by the area sensor. FIG. 5 is a diagram for explaining a level of reflection luminance on a screen 41. FIG. 5 is a diagram for explaining a level of reflection luminance on a screen 41. FIG. 5 is a diagram for explaining a level of reflection luminance on a screen 41. FIG. 5 is a diagram for explaining a level of reflection luminance on a screen 41. FIG. 3 is a main flowchart of a contrast correction sequence performed by a control unit 101 of the projector device 1 shown in FIG. It is a flowchart of a contrast measurement sequence. It is a flowchart of the detection process of a projection screen light quantity. It is a flowchart of a contrast value calculation process. It is a flowchart of a contrast adjustment control sequence. It is a flowchart of a contrast down adjustment control sequence. It is a flowchart of a contrast-up adjustment control sequence.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projector apparatus, 10 ... Illumination optical system, 11 ... Lamp, 12 ... IR cut mirror, 13 ... Condenser lens, 14 ... Color wheel, 15 ... Integrator rod, 16 ... Relay lens, 17 ... Illumination system stop, 18 ... Polarization Conversion element, 19 ... transmission type LCD, 20 ... mirror part, 20a ... total reflection mirror, 20b ... half mirror, 21 ... area sensor, 30 ... projection optical system, 31 ... projection system stop, 32 ... zoom lens, 33 ... focus Lens ... 41 ... Screen 101 ... System control microcomputer (control part) 102 ... AC power input part 103 ... Booster circuit 104 ... Constant current drive circuit 105 ... Color wheel drive mechanism 106 ... Color wheel filter phase detection Mechanism 107: Illumination system diaphragm drive mechanism 108: Detection of illumination system diaphragm aperture 109: Mirror drive mechanism, 110: Mirror slide position detection mechanism, 111 ... Projection system stop drive mechanism, 112 ... Projection system stop opening detection mechanism, 113 ... Zoom lens drive mechanism, 114 ... Zoom lens position detection mechanism, 115 ... focus lens drive mechanism, 116 ... focus lens position detection mechanism, 120 ... environmental light quantity detection mechanism, 130 ... calibration switch.

Claims (12)

In a projector device that projects an image according to input image information onto a screen,
Light source means for emitting illumination light;
Spatial modulation means for modulating the illumination light emitted by the light source means according to input image information to generate projection light;
Projection optical means for projecting the projection light generated by the spatial modulation means;
A light amount detection means for detecting a display light amount reflected from an image portion on the screen surface projected by the projection optical means and an environmental light amount reflected from a portion other than the image on the screen surface;
Zoom variation means for varying the zoom magnification when the projection optical means projects an image, and
The zoom variation means includes
A projector apparatus, wherein the zoom magnification of the projection optical means is varied so that a contrast value, which is a ratio between a display light quantity detected by the light quantity detection means and an environmental light quantity, falls within a predetermined range. The zoom variation means includes
The projector apparatus according to claim 1, wherein the zoom magnification is changed in a reduction direction when the ambient light becomes bright or the projection light becomes dark. The zoom variation means includes
The projector apparatus according to claim 1, wherein when the ambient light becomes dark or the projection light becomes bright, the zoom magnification is changed in the enlargement direction. The light amount detecting means is an area sensor,
The zoom variation means includes
The projector according to claim 1, wherein the contrast is detected by capturing at least a boundary portion of the projection image by the area sensor. A calibration switch capable of instructing an operator to start the operation of the zoom variation means;
The zoom variation means includes
The projector apparatus according to claim 1, wherein the zoom magnification of the projection optical unit is changed after the calibration switch is pressed. A diaphragm control means capable of limiting the luminous flux of the projection light projected by the projection optical means;
A light amount control means capable of controlling the amount of illumination light emitted by the light source means;
The zoom variation means, the aperture control means, and the light source control means are linked so that the contrast value, which is the ratio between the display light quantity detected by the light quantity detection means and the environmental light quantity, falls within a predetermined range. Control means to operate;
The projector according to claim 1, further comprising: A zoom control method according to calibration in the projector device according to claim 1,
A first step of turning off the light source means;
A second step of measuring a first light amount reflected from the screen surface with the light source unit turned off by the light amount detection unit;
A third step of turning on the light source means;
A fourth step of measuring, by the light amount detecting means, a second light amount reflected from an image portion on the screen surface projected by the projection optical means with the light source means turned on;
A fifth step of obtaining a contrast value from the ratio of the detected first light quantity and second light quantity;
When the contrast value obtained in the fifth step is smaller than a value within a predetermined range, the zoom variation unit varies the zoom magnification of the projection optical unit in the direction of reducing,
A sixth step of changing the zoom magnification of the projection optical means in the direction of enlarging by the zoom changing means when the contrast value obtained in the fifth step is larger than a value within a predetermined range;
A zoom control method comprising:   The zoom control method according to claim 7, wherein the first to sixth steps operate after the projector apparatus is powered on.   9. The zoom control method according to claim 8, wherein the value within the predetermined range is a contrast value obtained in the fifth step after power is turned on.   The zoom control method according to claim 7, wherein the first to sixth steps operate after the calibration switch is turned on.   8. The first to sixth steps are repeated until a contrast value, which is a ratio between a display light amount detected by the light amount detection means and an environmental light amount, becomes equal to a value within a predetermined range. The zoom control method described. A zoom control method according to calibration in the projector device according to claim 6,
A first step of operating the zoom variation means so that the contrast value is within a predetermined range;
A second step of operating the aperture control means so that the contrast value is within a predetermined range when the contrast value is not within the predetermined range in the first step;
A third step of operating the light source control means so that the contrast value is within a predetermined range when the contrast value is not within the predetermined range even in the second step;
A zoom control method comprising:

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