JP2003161869A - Focal point/field angle adjusting apparatus for lens exchangeable projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a focal point/field angle adjusting apparatus for a lens exchangeable projector capable of automatically correcting defocusing/dislocation of field angle, by transmitting the temperature information on each part of a lens side to a projector body side, related to a projector of which lenses of the same kind and same series, having common focal point/field angle, are exchangeable. <P>SOLUTION: The signals of a frame temperature sensor 10 of a lens frame 8, a lens temperature sensor 12, and an information storage circuit 11 are inputted in a control circuit 16 through a connector when a projector is attached. While the projector is attached, a mount is shifted by a drive circuit 18 and a motor 19 to adjust the focal point and field angle of the lens of the series based on the lens information transmitted from the information storage circuit 11. Upon receiving the temperature information transmitted in real time, the correction amount for the mount listed in the temperature correspondence in the table that agrees with the temperature is read, to correct the focal point/ field angle deviated due to temperature rising. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interchangeable lens type projector, and more specifically, a device for adjusting a focus position and an angle of view of a projector capable of exchanging lenses of the same type and series having a common focus position and angle of view. Regarding

[0002]

2. Description of the Related Art In the case of the same type and series of interchangeable lens projectors having the same focal position and angle of view as described above, if they have the same design, they should have the same focus and angle of view. They do not always match due to processing accuracy issues. Moreover, unlike the camera lens, the focus of the projection plane is greatly shifted just by changing the focal position by several mm. Also, when stacking screens with a stack or the like, the angle of view must be finely adjusted, and it is a matter of course that work that is not necessary should be done.

FIG. 7 is a view showing an example of the configuration of a conventional lens barrel for matching the focus position and the angle of view when the lens is exchanged.
(A) shows the case where a fine adjustment zoom ring is used, and (b) shows the second
The case where a lens barrel is provided is shown. In (a), a fine adjustment zoom ring 31 is provided outside the lens barrel 33 of the lens 30.
Is provided. The angle of view of all lenses is unified by doubling the zoom ring. In (b), the second lens barrel 35 is provided outside the first lens barrel 34, and the lens barrel is doubled so that all lenses have the same projection distance at the same projection distance.

FIG. 8 is a diagram showing another example of the configuration of a conventional lens barrel when the lens is replaced. By having the ROM 37 in which information is written in the lens 38, the variation of each lens is absorbed. As described above, conventionally, the information is written in the ROM and is corrected by the lens barrel on the lens side.

[0005]

By the way, as a high-definition and high-resolution interchangeable lens projector, a system in which the lens side is not focused is implemented. This is to get the focus by moving the mount back and forth on the camera side. At present, a pattern signal for identifying a lens is electrically detected. That is, the focus position is adjusted by detecting the level provided with the zoom position detecting sensor or the volume.

[0006] The above-mentioned projector, when enlarging and projecting a film size image to 200 inches to 500 inches,
A slight focus shift has a large effect on the screen, and the focus shift increases. Conventionally, position detection of out-of-focus is performed with a volume. The high-brightness type used in a movie theater uses a lamp that generates a large amount of heat. Therefore, when projected for a long time, the temperature of the lens barrel / lens rises due to the heat from the lamp, the lens barrel expands, and the lens is distorted and the focus gradually shifts. Conventionally, no particular measures have been taken against temperature, but with projector lenses, the temperature inside the lens barrel increases more and more as the brightness of the projector becomes higher, so that temperature measures are required. .

An object of the present invention is to provide an information storage circuit for a lens, a lens frame, and a temperature sensor for the lens on the lens barrel side in a lens interchangeable projector in which the same focal point or the same series of lenses have the same focal position and angle of view. The focus position and angle of view of a lens-interchangeable projector that can automatically adjust the focus shift and the angle of view shift by sending the information to the projector body by providing the information. To provide an adjusting device.

[0008]

In order to achieve the above object, the focus position of the lens-interchangeable projector according to the present invention
The angle-of-view adjusting device is a lens-interchangeable projector that is equipped with interchangeable lenses of the same type and series that share the same focus position and angle of view, and that adjusts the focus position and angle of view of the mounted lens. A storage unit that stores the lens information, a lens frame temperature sensor that detects the lens frame temperature, and a lens temperature sensor that detects the lens temperature are provided in the frame, and when the lens is attached, the lens unit sends the information to the projector body side. The focus position and angle of view are adjusted by moving the mount on the projector side back and forth according to the lens information, and after mounting, each temperature signal sent to the projector body side from the two temperature sensors is received, and each temperature in the lens is received. The mount drive amount corresponding to the temperature is read by referring to the table describing the mount drive amount corresponding to It is configured to adjust a deviation of the focus position and the angle caused by the temperature rise by driving the Ekuta body side mount. Further, the lens frame temperature sensor in the present invention is arranged on the inner circumferential wall forming the lens frame, and the lens temperature sensor is arranged on the end portion of the lens. Further, according to the present invention, in the above configuration, the infrared projector and the AF device are provided in the projector main body, a predetermined pattern is projected to the outside of the image projection area on the screen, the pattern is received by the AF device, and the setting is made when the lens is attached. The focusing operation is performed for the selected angle of view.

[0009]

According to the above construction, the lenses of the same type and the same series can achieve the same focal point and the same angle of view, and inform the temperature of the projector body in real time by incorporating the temperature sensor. This can provide an environment in which the focus can be automatically corrected. Therefore, by mounting only the circuit / sensor portion, the electric portion inside the lens barrel becomes simple and it is not necessary to have a temperature correction optical system, so that the movable portion on the lens side can be reduced.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an internal structure of a lens-interchangeable projector to which a focus position / angle-of-view adjusting device according to the present invention is applied. This drawing only describes the parts directly related to the present invention. The lens barrel 8 is an interchangeable lens and is mounted on the mount 3 of the DLP projector 1. The light emitted from the light source 6 of the DLP projector 1 is
The light is reflected by the reflection mirrors 5 and 4 and enters the DMD 7.

An image signal (not shown) is input to the DMD 7, and the incident light is modulated by the image signal. The modulated light is magnified by the lens 2 and projected on a screen (not shown). The lamp 6 has an output of several KW, has a large amount of heat generation, and there is a portion in the lens barrel 8 which reaches 100 ° C., for example. The DMD is a collection of hundreds of thousands to millions of extremely small mirrors (reflecting mirrors) each having a size of 16 micrometers, and each mirror reflects one by one.
By repeating non-reflection, the DMD image is projected on the screen. The DLP is usually composed of a light source, a condenser lens, a DMD and a projection lens.

An AF auxiliary light 14 composed of an infrared lamp or an LED is installed on the upper part of the projector body,
The IR projection lens 20 projects a specific pattern outside the image projection area of the screen. On the other hand, an AFIC 13 that detects infrared light is provided, and the reflected light of a specific pattern passes through the light projecting lens 2 and is further reflected by the reflection mirrors 21 and 22 to enter the AFIC 13.

FIG. 2 is a schematic view showing an arrangement example of temperature sensors provided in the lens barrel. A lens frame temperature sensor 10 is provided on the inner wall of the lens frame of the lens frame 8. Also,
A lens temperature sensor 12 for detecting the temperature of the lens is provided at an intermediate position between the lens groups 2b and 2C. Further, an information storage circuit 11 is provided, and the information storage circuit 11 stores lens information such as lens type, focal length, and aperture. The outputs of these sensors and the information storage circuit 11 are output to the projector main body through a connector (not shown).

FIG. 3 is a diagram for explaining a focusing method of a lens-interchangeable projector to which the focus position / angle-of-view adjusting device according to the present invention is applied. Infrared lamp or LED1
4, a chart (not shown) is projected on the screen 27 through the IR projection lens 20. As shown in FIG. 4, the image circle 23 formed on the screen 27 includes a region 24 used for projection. The chart is displayed in the area 25 used for AF, which is outside the area 24 used for this projection. This chart passes through the light projecting lens 2, is reflected by the reflection mirrors 21 and 22, and enters the AFIC 13.

FIG. 5 is a block diagram showing an embodiment of a circuit of a focus position / angle-of-view adjusting device of an interchangeable lens type projector according to the present invention. When the lens barrel 8 is mounted, the temperature signal of the lens barrel temperature sensor 10 of the lens barrel 8, the lens temperature sensor 12, and the signal indicating the lens information of the information storage circuit 11 are input to the control circuit 16 via the connector. It At the time of mounting, the control circuit 16 controls the drive circuit 18 to drive the motor 19 by setting the focus position and the angle of view of the lens of the series to be adjusted according to the lens information sent from the information storage circuit 11. The mount 3 is moved via a gear (not shown). With this, it is possible to adjust to a predetermined focus position and angle of view at the time of mounting.

The AF operation can be activated by pressing a button (not shown). AF auxiliary light 14
Infrared light is emitted from the device, the reflected light of the projected chart is incident on the AFIC 13, and its information is input to the control circuit 16. The control circuit 16 controls the drive circuit 18 based on the AF information to drive the motor 19 to move the mount position and bring the lens barrel 8 to the focus position. A table 17a of the memory unit 17 describes mount correction amounts with respect to lens and lens frame temperatures for lenses of the same type and the same series. The control circuit 16 receives the temperature information sent in real time and reads the mount correction amount described in correspondence with the temperature in the table that matches this temperature.

The control circuit 16 controls the drive circuit 18 by using the read correction amount as a correction signal to control the motor 19
To drive. The mount 3 can be moved to correct the focal position and the angle of view that are deviated due to the temperature rise. The mode of temperature rise in the lens barrel differs depending on the ambient temperature and the installation position, and is drive-controlled so that an appropriate focus position and angle of view can be always maintained based on temperature information input in real time. It should be noted that the control interval driven by the temperature information is not continuous and may be performed at regular intervals.

FIG. 6 is a flow chart for explaining the operation of the lens-interchangeable projector to which the focus position / angle-of-view adjusting device according to the present invention is applied. It is assumed that the lens is mounted and the angle of view is set to a predetermined value. When the AF is driven (step (hereinafter referred to as “S”) 601), the AFIC 13
Performs distance measurement based on the received information (S602), and the distance measurement information is sent to the control circuit 16. The control circuit 16 controls the drive circuit 18 to drive the motor 19 to adjust the focus position based on the distance measurement information (S603). As a result of driving, it is determined whether or not focus is achieved (S604). If not in focus, the process returns to S602 and the same operation is repeated to bring the lens barrel 8 to the in-focus position.

Next, the control circuit 16 receives the lens frame temperature information and the lens temperature information sent from the lens barrel 8 and determines whether or not the temperature has changed to a predetermined temperature (S605). Table 1 of the memory unit 17 when the temperature changes by a predetermined temperature or more
Data is read from 7a and distance measurement is performed (S606, S
607). Then, it is determined whether or not the subject is in focus (S6
08). When it is in focus, the temperature change is monitored again. If the lens is not in focus, the lens barrel 8 is driven (S609), and focus determination is performed (S610). As a result, if the focus is not achieved, the process returns to the temperature change monitoring of S605. When the focus is achieved, the read table data is corrected and the temperature change monitoring is started (S611).

[0020]

As described above, according to the present invention, the interchangeable lens of the same type and the same series having the same focal position and angle of view is mounted, and the lens is exchanged to adjust the focal position and angle of view of the mounted lens. A projector of a type, in which a storage unit that stores the lens information, a lens frame temperature sensor that detects the lens frame temperature, and a lens temperature sensor that detects the lens temperature are provided in the lens lens frame, Unit adjusts the focus position and angle of view by moving the mount on the projector side back and forth according to the lens information sent to the projector body side, and after mounting the temperature signals sent to the projector body side from the two temperature sensors Then, by referring to the table in which the mount drive amount corresponding to each temperature in the lens is described, the drive of the mount corresponding to the sent temperature is performed. It reads the amount and adjusts the displacement of the focus position and the angle caused by the temperature rise by driving the mount of the projector main body. Then, a predetermined pattern is projected by infrared rays outside the image utilization area of the screen, and the reflected light is received by the AF device to enable the AF operation.

Therefore, when the lens is exchanged, it is possible to prevent the focus shift from being conspicuous by the AF and to prevent the angle of view from shifting, and in the case where the temperature of the lens barrel increases with time, an appropriate focus position and The angle of view can be maintained. Further, since the present invention can be realized by mounting only the information storage circuit and the temperature sensor on the lens barrel, the electric circuit of the lens barrel becomes simple and the temperature correcting optical diameter is not mounted, so that the lens barrel It is possible to simplify the mechanism of the lens barrel without providing a movable mechanism section in the. In the conventional TTL, an optical system for splitting light such as a half mirror is provided on the optical path by using an image actually projected. Therefore, deterioration of the projected image could not be prevented. However, according to the present invention, since the area that is not used at the time of projection is used, it is possible to realize the TTL-AF mode while maintaining the lens performance without degrading the projected image.

[Brief description of drawings]

FIG. 1 is a schematic view showing an internal structure of a lens-interchangeable project to which a focus position / angle-of-view adjusting device according to the present invention is applied.

FIG. 2 is a schematic view showing an arrangement example of temperature sensors provided in a lens barrel.

FIG. 3 is a diagram for explaining a focusing method of a lens-interchangeable projector to which the focus position / angle-of-view adjusting device according to the present invention is applied.

FIG. 4 is a diagram for explaining an AF use area on a screen.

FIG. 5 is a block diagram showing an embodiment of a circuit of a focus position / angle-of-view adjusting device of a lens-interchangeable projector according to the present invention.

FIG. 6 is a flowchart for explaining the operation of the lens-interchangeable project to which the focus position / angle-of-view adjusting device according to the present invention is applied.

7A and 7B are diagrams showing a configuration example of a conventional lens barrel that matches a focus position and an angle of view when a lens is exchanged. FIG. 7A shows a case where a fine adjustment zoom ring is used, and FIG. 7B shows a second lens barrel. The case where each is provided is shown.

FIG. 8 is a diagram showing another example of the configuration of a conventional lens barrel when replacing a lens.

[Explanation of symbols]

1 DLP projector 2,38 lenses 3 mount 4,5 reflection mirror 6 lamps (light source) 7 DMD (Digital Micromirror Device) 8 lens frame 10 Lens frame temperature sensor 11 Information storage circuit 12 Lens temperature sensor 13 AFIC 14 AF auxiliary light (infrared lamp or LED) 15 Projector body 16 Control circuit 17 Memory section 17a table 18 Drive circuit 19 motor 20 IR projection lens 21,22 reflection mirror 23 image circles 24 Projection use area 25 AF usage area 26 Chart (Target) 27 screen 28 Projection plane 31 Zoom ring for fine adjustment 33 lens barrel 34 First lens barrel 35 Second lens barrel 37 ROM

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) G02B 7/08 G02B 7/08 C 7/28 G03B 21/00 D G03B 13/36 21/14 D 21 / 00 G02B 7/11 H 21/14 G03B 3/00 A

Claims (3)

[Claims] 1. A lens-interchangeable projector in which interchangeable lenses of the same type and the same series having a common focus position and angle of view are mounted and the lens is interchangeable in type to adjust the focus position and angle of view of the mounted lens. A storage unit for storing the lens information, a lens frame temperature sensor for detecting the lens frame temperature, and a lens temperature sensor for detecting the lens temperature are provided inside, and when the lens is attached, the data is sent from the storage unit to the projector body side. The focus position and angle of view are adjusted by moving the mount on the projector side back and forth according to the lens information, and after mounting, each temperature signal sent to the projector body side from the two temperature sensors is received and By referring to the table describing the corresponding mount drive amount, the mount drive amount corresponding to the temperature sent is read and A focal position / angle-of-view adjustment device for a lens-interchangeable projector, which is configured to adjust a shift of a focal position and an angle of view caused by a temperature rise by driving a mount on a vector body side. 2. The lens according to claim 1, wherein the lens frame temperature sensor is arranged on a circumferential inner wall forming a lens frame, and the lens temperature sensor is arranged on an end portion of the lens. Focus position and angle of view adjustment device for interchangeable projectors. 3. An infrared projector and an AF device are provided in the main body of the projector, a predetermined pattern is projected outside the image projection area on the screen, the pattern is received by the AF device, and set when the lens is attached. 3. A focusing operation is performed with respect to an angle of view.
A focus position / angle-of-view adjustment device for the lens interchangeable projector described above.