JP2005062455A - Projector, ranging method of projector and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make ranging accuracy always sufficiently high regardless of a distance from a projection position and to exactly focus an image to be projected. <P>SOLUTION: The projector is equipped with a spatial optical modulation element 36, a light source lamp 37 and a projection lens 12 which form the light image based on an inputted image signal and project and display the image, an Ir signal transmission section 14 and Ir signal reception section 15 which measure the distance from the projection position thereof, and a control section 44 which preliminarily measures the distance up to the projection position, selects the corresponding distance range from a plurality of preset distance ranges, measures the distance up to the projection position by as much as a plurality of preset times in correspondence to the selected distance range, and calculates the distance up to the projection position from the values of the distances up to the projection positions for the plurality of the times. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projection apparatus having an automatic focusing function for a projected image, a distance measuring method for the projection apparatus, and a program.

Conventionally, in a portable projection device, an ultrasonic transmission / reception device is used to measure the distance from the propagation time of an ultrasonic signal reflected by the screen to the screen, and the focus of the projection lens is adjusted based on the measured distance. Is considered. (For example, Patent Document 1)
JP-A-4-338706

  However, not only ultrasonic waves but also devices that transmit and receive infrared light, for example, when measuring the distance to the screen from the time difference obtained by transmitting and receiving them, the accuracy of the distance obtained is The distance measurement accuracy varies greatly. Specifically, the distance is large, and as the screen is moved away from the apparatus, the distance measurement accuracy is remarkably lowered.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to ensure that the distance measurement accuracy is always sufficiently high regardless of the distance to the projection position, and to accurately focus the image to be projected. It is an object of the present invention to provide a projection apparatus, a distance measuring method for the projection apparatus, and a program that can be used.

  According to the first aspect of the present invention, there are provided projection means for forming and projecting a light image based on an input image signal, distance measurement means for measuring a distance to a projection position by the projection means, and distance measurement means. The distance to the projection position is measured by the first distance measurement control means for selecting a corresponding distance range from a plurality of preset distance ranges, and the distance range selected by the first distance measurement control means. Correspondingly, a second distance measurement control means for measuring the distance to the projection position by the distance measurement means for a plurality of preset times, and a plurality of projection positions obtained by the second distance measurement control means. And a distance calculation means for calculating a distance from the distance value to the projection position by the projection means.

  The invention described in claim 2 further comprises photographing means having an automatic focusing function for photographing an image projected and displayed by the projecting means in the invention described in claim 1, wherein the distance measuring means comprises the above-mentioned distance measuring means. It is characterized in that the distance from the automatic focusing position of the captured image obtained by the automatic focusing function of the imaging means to the projection position is measured.

  According to a third aspect of the present invention, in the first aspect of the invention, the second distance measurement control means projects more times as the distance range selected by the first distance measurement control means is farther. The distance to the position is measured.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the distance calculation frequency is characterized in that an average value of distances to a plurality of projection positions is a distance to the projection position.

  The invention according to claim 5 is a distance measuring method of a projection device that forms and displays a light image based on an input image signal, and measures a distance to a projection position, and sets a plurality of preset distances. A first distance measurement control step of selecting a corresponding distance range from the distance range, and a distance to the projection position by a plurality of times set in advance corresponding to the distance range selected in the first distance measurement control step A second distance measurement control step for measuring, and a distance calculation step for calculating a distance to the projection position from a plurality of distance values to the projection position obtained in the second distance measurement control step It is characterized by.

  The invention described in claim 6 is a program executed by a computer built in a projection apparatus that forms and displays an optical image based on an input image signal, and measures a distance to a projection position and is set in advance. A first distance measurement control step for selecting a corresponding distance range from a plurality of distance ranges, and projection positions for a plurality of times set in advance corresponding to the distance range selected in the first distance measurement control step A second distance measurement control step for measuring the distance to the distance, and a distance calculation step for calculating a distance to the projection position from a plurality of distance values to the projection position obtained in the second distance measurement control step; Is executed by a computer.

  According to the invention described in claim 1, by setting the number of distance measurement corresponding to the distance range in advance, the distance measurement accuracy is always sufficiently high regardless of the distance to the projection position, and the image to be projected is It becomes possible to focus accurately.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the distance from the actually projected image state to the projection position is measured by the automatic focusing function of the photographing means. Since it did in this way, the distance value considered to be more suitable for projection can be obtained.

  According to the third aspect of the invention, in addition to the effect of the first aspect of the invention, the distance measurement accuracy is relatively increased by performing the distance measurement as many times as much in the far distance range where the accuracy is lowered. Can be compensated for, and high ranging accuracy can be maintained in any distance range.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, the distance to the projection position can be calculated from the result of multiple times of distance measurement by a very simple calculation.

  According to the fifth aspect of the present invention, the distance measurement accuracy is always sufficiently high regardless of the distance to the projection position, and the projected image can be accurately focused.

  According to the sixth aspect of the invention, the distance measurement accuracy is always sufficiently high regardless of the distance to the projection position, and the projected image can be accurately focused.

  Hereinafter, an embodiment in which the present invention is applied to a projector apparatus will be described with reference to the drawings.

  FIG. 1 shows an external configuration of a projector apparatus 10 according to the embodiment. As shown in FIG. 1A, a projection lens 12, a photographing lens 13, an Ir transmitter 14, and an Ir receiver 15 are disposed on the front surface of a rectangular parallelepiped main body casing 11.

  The projection lens 12 is for projecting a light image formed by a spatial light modulation element such as a micromirror element to be described later. Here, the focus position and the zoom position (projection angle of view) can be arbitrarily changed. Shall.

  The photographic lens 13 is an optical lens system that has an imaging angle of view equivalent to at least the maximum projection angle of view of the projection lens 12 and can be automatically focused and zoomed. A solid-state imaging device (not shown) such as a CCD is used here. An optical image including the projection image of the projection lens 12 is formed on the imaging surface.

The Ir transmitter 14 includes, for example, an LED (light emitting diode) and a drive circuit thereof, and transmits infrared light (Ir) during distance measurement at the time of setting.
The Ir receiving unit 15 receives infrared light superimposed with a key operation signal from the Ir transmitting unit 14 or a remote controller of the projector device 10 (not shown).

  The Ir transmitter 14 and the Ir receiver 15 increase the accuracy by trigonometry in order to acquire the time difference from the transmission of infrared light to the reflection of the target screen and the reception of the reflected light. The projector apparatus 10 is arranged so as to be positioned at both ends of the projector apparatus 10 with a distance as far as possible.

  A zoom ring 16 and a focus ring 17, both of which are dial rings, a main body main key / indicator 18, a speaker 19, and a cover 20 are disposed on the upper surface of the main body casing 11.

The zoom ring 16 and the focus ring 17 are used when manually operating the zoom position and the focus position of the image projected and displayed by the projection lens 12.
The main body main key / indicator 18 is an indicator composed of keys for switching on / off of power, automatic / manual, input switching, and the like, and LEDs for displaying the operation state by turning on / off and lighting color. It becomes.

The speaker 19 amplifies and outputs the presentation contents and the sound when the recorded moving image is reproduced.
The cover 20 opens and closes when a subkey (not shown) is operated and when a memory card described later is inserted or removed. The sub key operates various detailed operations that cannot be set by the main body main key / indicator 18 without using a remote controller of the projector device 10 (not shown).

Further, as shown in FIG. 1B, an input / output connector portion 21, an Ir receiving portion 22, and an AC adapter connecting portion 23 are disposed on the back surface of the main body casing 11.
The input / output connector unit 21 includes, for example, a USB terminal for connection with an external device such as a personal computer, a mini D-SUB terminal for video input, an S terminal, an RCA terminal, a stereo mini terminal for audio input, and the like. Become.

Similar to the Ir receiver 15, the Ir receiver 22 receives infrared light on which key operation signals from a remote controller (not shown) are superimposed.
The AC adapter connection unit 23 connects a cable from an AC adapter (not shown) serving as a power source.

In addition, a pair of fixed leg portions 24 and 24 are attached to the lower surface of the main body casing 11 on the rear side, and an adjustment leg portion 25 capable of height adjustment is attached to the front side.
By adjusting the screw rotation position manually, the adjustment leg 25 accurately adjusts the vertical direction component of the projection direction of the projection lens 12 and the photographing direction of the photographing lens 13, that is, the elevation angle.

  Next, the functional configuration of the electronic circuit of the projector apparatus 10 will be described with reference to FIG. In the drawing, in the projection mode, which is the basic mode, image signals of various standards input from the input / output connector unit 21 are input to the image conversion unit 32 via the input interface (I / F) 31 and the system bus SB. After being unified into an image signal of a predetermined format, it is sent to the display encoder 33.

  The display encoder 33 develops and stores the transmitted image signal in the video RAM 34, generates a video signal from the stored contents of the video RAM 34, and outputs the video signal to the display drive unit 35.

  The display driving unit 35 drives the spatial light modulation element (SOM) 36 at an appropriate frame rate, for example, 30 [frame / second] corresponding to the transmitted image signal. By irradiating the element 36 with white light with high luminance emitted from a light source lamp 37 such as an ultra-high pressure mercury lamp, a light image is formed by the reflected light, and the light is formed on a screen (not shown) via the projection lens 12. Projected display.

However, the projection lens 12 is driven by the lens motor (M) 38 to appropriately move the zoom position and the focus position.
In the photographing mode for photographing the projected image, the imaging surface of the CCD 40, which is a solid-state imaging device, is disposed on the optical axis of the photographing lens 13 whose zoom position and focus position are moved by the lens motor (M) 39. Then, an image signal of a corresponding analog value is generated from the CCD 40 and sent to the process circuit 41.

  The process circuit 41 digitizes the image signal obtained by the CCD 40, performs color process processing including pixel interpolation processing and γ correction processing, generates a digital luminance signal Y and color difference signals Cb and Cr, and The data is output to the image compression / decompression unit 42 via the system bus SB.

  The image compression / decompression unit 42 compresses the luminance and color difference signals by a process such as ADCT or Huffman encoding, and the obtained image data is attached to a memory card 43 that is detachably mounted as a recording medium of the projector device 10. Write sequentially.

  In the reproduction mode in which the image data recorded on the memory card 43 is read out and projected and displayed, individual image data constituting a series of moving images recorded on the memory card 43 is read out in units of one frame. The compression / decompression unit 42 decompresses image data that has been compressed by a procedure that is completely opposite to the procedure of data compression in the recording mode, sends the decompressed image data to the display encoder 33, the video RAM 34, and the display drive unit 35. The spatial light modulation element 36 is driven via the light source, and the light emitted from the light source lamp 37 is irradiated to form a light image with the reflected light, and is projected and displayed via the projection lens 12.

  Note that the recording medium of the projector device 10 may not be detachable like the memory card 43 but may be a fixed built-in type semiconductor memory, and a large-capacity built in a main body such as a hard disk device. It may be a thing.

  The control unit 44 controls all the operations of the circuits. The control unit 44 is a ROM that stores a CPU and an operation program executed by the CPU including a distance measurement process, which will be described later, in a fixed manner. And a RAM used as a work memory.

An audio processing unit 45 is also connected to the control unit 44 via the system bus SB.
The sound processing unit 45 includes a sound source circuit such as a PCM sound source, converts the sound data given in the projection mode and the reproduction mode into analog, and drives the speaker 19 to emit loud sounds.

  The main body main key / indicator 18 and the main body subkey provided in the cover 20 constitute a key / indicator section 46, and the Ir transmitting section 14, Ir receiving section 15, and Ir receiving section 22 provide an Ir transmitting / receiving section 47. These key operation signals and infrared light reception signals are both sent directly to the control unit 44.

  Next, the operation of the above embodiment will be described.

  FIG. 3 shows a process related to the distance measuring process when the projected image by the projection lens 12 is automatically focused in accordance with the distance from the screen (not shown) after the installation of the projector apparatus 10 is completed as the initial setting of the projection mode. This indicates the contents, and is mainly executed by the control unit 44 based on an operation program stored in the internal ROM.

  Initially, the IR transmitter 14 emits infrared light in the direction of the screen, the reflected light is received by the Ir receiver 15, and the time difference is measured to measure the time difference. Is executed (step S01).

  Then, whether the distance to the obtained screen is 1 [m] or less (step S02), whether it is far from 1 [m] and 2 [m] or less (step S03), far from 2 [m] and 3 It is judged whether it is [m] or less (step S04), or farther than 3 [m] and 4 [m] or less (step S05) until it falls within the corresponding range.

If it is determined in step S02 that the distance to the screen is 1 [m] or less, the number n of times of distance measurement as the subsequent second stage is set to “3” (step S06).
If it is determined in step S03 that the distance to the screen is longer than 1 [m] and 2 [m] or less, the number n of times of distance measurement as the subsequent second stage is set to “5” ( Step S07).

  When it is determined in step S04 that the distance to the screen is longer than 2 [m] and 3 [m] or less, the number n of times of distance measurement as the subsequent second stage is set to “10” ( Step S08).

  If it is determined in step S05 that the distance to the screen is greater than 3 [m] and less than or equal to 4 [m], the subsequent number n of times of distance measurement as the second stage is set to “20” ( Step S09).

  If it is determined in step S05 that the distance to the screen is not more than 3 [m] and not less than 4 [m], the distance to the screen is more than 4 [m]. The number n of times of distance measurement as the subsequent second stage is set to “30” (step S10).

  Thus, after setting the number n of distance measurement in any of the above steps S06 to S10, the distance measurement to the screen is performed by the Ir transmission unit 14 and the Ir reception unit 15, and the distance obtained as a result is held. (Step S11), the number of times n is set to “−1” (step S12), and it is confirmed that the number of times n after the update setting is not “0” (step S13). Is repeatedly executed, distance measurement as the second stage is executed n times.

  Then, after executing the set n times of distance measurement, the total value of the measured values of n times is divided by n in step S13 to calculate the average value of the distance (step S14), and this is focused. The focus position of the photographic lens 13 is moved by the lens motor 38 as a distance (step S15), and the series of operations related to the distance measurement processing at the time of initial setting is completed.

  As described above, based on the distance value obtained by the distance measurement in the first stage, the distance measurement result after performing the distance measurement in the second stage a plurality of times set in advance corresponding to the distance range. Since the final distance value is calculated from the above, setting the appropriate number of distance measurements corresponding to the distance range ensures that the distance measurement accuracy is always sufficiently high regardless of the distance to the projection position. This makes it possible to focus the projected image accurately.

  In addition, more specifically, in a distant distance range where accuracy is reduced by one distance measurement, the distance measurement accuracy is relatively compensated by performing the distance measurement many times. High ranging accuracy can be maintained even in the distance range.

  Note that the setting of each distance range shown in FIG. 3 and the setting of the number of distance measurements n corresponding to these distance ranges are merely examples, and can be easily changed and set appropriately according to the characteristics of the projection system of the projector apparatus 10 and the like. Can do.

  In the operation of the above embodiment, the distance to the screen (not shown) of the projection target is calculated from the time difference between the transmission of the infrared light at the Ir transmitter 14 and the implementation of the reflected light at the Ir receiver 15. As described above, when performing such an active distance measurement, the propagation speed in air is significantly lower than that of infrared light as compared to infrared light. It is good also as what transmits / receives the ultrasonic wave in which ranging is possible.

  Further, the projector apparatus 10 has a photographing system circuit including the lens motor 39, the photographing lens 13, the CCD 40, and the process circuit 41 without performing the above-described active type distance measurement. Therefore, in a state where the test pattern image prepared in advance in the control unit 44 is projected onto the screen to be projected from the projection lens 12, the image is photographed by driving the above-described photographing system circuit. The distance to the screen can be measured by performing distance measurement associated with the automatic focusing process of the method.

  Therefore, it is possible to obtain the distance value to the screen each time by the automatic focusing process based on the driving of the circuit of the photographing system, and measure the distance from the actually projected image state to the projection position in this way. Thus, it is possible to obtain a distance value that seems to be more suitable for projection.

  In the above embodiment, the correct distance value is obtained by simply calculating the average value from the distance values obtained by the plurality of distance measurements in the second stage. Thereby, it is possible to calculate the distance from the result of multiple times of ranging to the projection position by a very simple calculation, but dare to calculate the average value, for example, the closer the distance to the screen, Since it is considered that the distance measurement accuracy is greatly lowered due to the deviation of the facing angle of the screen with respect to the projector device 10, the distance measurement result may be weighted according to the distance range. It is good also as what reflects in the frequency | count of performing.

  The above embodiment describes the case where the present invention is applied to a projector apparatus. However, the present invention is not limited to this, and for example, photographing a product as a still life that requires more precise distance measurement. It can be applied to a digital still camera or the like that performs the above.

  In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, at least one of the problems described in the column of the problem to be solved by the invention can be solved, and described in the column of the effect of the invention. In a case where at least one of the obtained effects can be obtained, a configuration in which this configuration requirement is deleted can be extracted as an invention.

1 is a perspective view showing an external configuration of a projector apparatus according to an embodiment of the present invention. The block diagram which shows the function structure of the electronic circuit of the projector apparatus which concerns on the same embodiment. The flowchart which shows the processing content at the time of the distance measurement which concerns on the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Projector apparatus, 11 ... Main body casing, 12 ... Projection lens, 13 ... Shooting lens, 14 ... Ir transmission part, 15 ... Ir reception part, 16 ... Zoom ring, 17 ... Focus ring, 18 ... Main body main key / indicator DESCRIPTION OF SYMBOLS 19 ... Speaker, 20 ... Cover, 21 ... Input / output connector part, 22 ... Ir receiving part, 23 ... AC adapter connection part, 24 ... Fixed leg part, 25 ... Adjustment leg part, 31 ... Input interface (I / F), 32 ... Image conversion unit, 33 ... Display encoder, 34 ... Video RAM, 35 ... Display drive unit, 36 ... Spatial light modulation element (SOM), 37 ... Light source lamp, 38, 39 ... Lens motor (M), 40 ... CCD, 41 ... process circuit, 42 ... image compression / decompression unit, 43 ... memory card, 44 ... control unit, 45 ... audio processing unit, 46 ... key / indicator unit, 4 ... Ir transmitting and receiving unit, SB ... system bus.

Claims (6)

Projection means for forming and projecting a light image based on the input image signal;
Ranging means for measuring the distance to the projection position by the projection means,
A first distance measurement control means for measuring a distance to the projection position by the distance measurement means, and selecting a corresponding distance range from a plurality of preset distance ranges;
A second distance measurement control means for measuring the distance to the projection position by the distance measurement means for a plurality of preset times corresponding to the distance range selected by the first distance measurement control means;
A projection apparatus comprising: a distance calculation unit that calculates a distance from a plurality of distances to the projection position obtained by the second distance measurement control unit to a projection position by the projection unit. Further comprising an imaging means having an automatic focusing function for taking an image projected and displayed by the projection means,
The projection apparatus according to claim 1, wherein the distance measuring unit measures a distance from an automatic focusing position to a projection position of a captured image obtained by the automatic focusing function of the imaging unit. The second distance measurement control means causes the distance to the projection position to be measured a greater number of times as the distance range selected by the first distance measurement control means is farther. Projection device. The projection apparatus according to claim 1, wherein the number of times of calculating the distance is an average value of distances to a plurality of projection positions as a distance to the projection position. A distance measuring method for a projection apparatus for forming and projecting a light image based on an input image signal,
A first distance measurement control step of measuring a distance to the projection position and selecting a corresponding distance range from a plurality of preset distance ranges;
A second distance measurement control step of measuring the distance to the projection position by a plurality of times set in advance corresponding to the distance range selected in the first distance measurement control step;
A distance measuring method for a projection apparatus, comprising: a distance calculation step of calculating a distance to the projection position from a plurality of distance values to the projection position obtained in the second distance measurement control step. A program executed by a computer built in a projection apparatus that forms and projects a light image based on an input image signal,
A first distance measurement control step of measuring a distance to the projection position and selecting a corresponding distance range from a plurality of preset distance ranges;
A second distance measurement control step for measuring the distance to the projection position by a plurality of preset times corresponding to the distance range selected in the first distance measurement control step;
A program that causes a computer to execute a distance calculation step of calculating a distance to a projection position from a plurality of distance values to the projection position obtained in the second distance measurement control step.

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