JP2944803B2 - Coordinate input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device for inputting position coordinate data of a cursor on a display device used in a personal computer or the like.

[0002]

2. Description of the Related Art A ball (sphere) is provided as a coordinate input device for cursor position coordinate data and graphic data on a display device, and the display position of the cursor on the display screen is arbitrarily changed by rotating the ball. What has been made to be able to do is known.

FIG. 3 is an exploded perspective view showing an example of such a coordinate input device. In the figure, a mounting member is formed on a housing 100, so that two rotators 101 </ b> X, 1 are provided on the edge of a concave portion 100 a provided substantially at the center of the housing 100 so as to be orthogonal to each other.
01Y is rotatably mounted. The rotating body 101X includes a shaft 102X, a roller 103X fixed to a substantially central portion thereof, and a chopper 104X fixed to an end thereof. The chopper 104X is provided with a plurality of slits. Rotating body 101Y also has shaft 1
02Y, roller 103Y, chopper 104Y,
It has the same configuration as the rotator 101X.

[0004] A ball 109 is arbitrarily rotatably fitted into the recess 100 a of the housing 100, and is mounted on the housing 100 from above the ball cover 110.

When the ball is fitted into the recess 100a, the rollers 10X and 101Y
3X and 103Y are pressed against the surface of the ball. Therefore, when the ball rotates, the rollers 103X and 103Y rotate and the choppers 104X and
104Y also rotates.

[0006] The housing 100 is placed and fixed on a substrate 105. On this substrate 105, photo interrupters 106X and 106Y, a control circuit 107, an output terminal 108 and the like are mounted. The photo-interrupter 106X has two protrusions facing each other, one light-emitting element is provided on one protrusion, and two light-receiving elements are provided on the other protrusion opposite to these light-emitting elements. The element receives light from one light emitting element, and the other light receiving element receives light from the other light emitting element. The photo interrupter 106Y has the same configuration.

A housing 100 is mounted on a substrate 105, and rotating bodies 101X and 101Y are provided in the housing 100.
Is installed, the chopper 104 of the rotating body 101X is mounted.
X enters between the two protrusions of the photointerrupter 106X, and similarly, the chopper 1 of the rotating body 101Y
Part of 04Y enters between the two protrusions of the photointerrupter 106Y. FIG. 4 shows the coordinate input device assembled in this manner. As is apparent from this, a part of the ball 109 protrudes from the cover 110 to the outside. Thus, the ball 109 can be rotated from the outside.

Therefore, as shown in FIG. 5, in the photo interrupter 106X, a part of the chopper 104X enters between the two light emitting elements and the two light receiving elements, and in the photo interrupter 106Y, the two light emitting elements and the two A part of the chopper 104Y enters between the light receiving element.

The ball 109 rotates and the chopper 104X
Rotates, a pulse signal having a frequency corresponding to the rotation speed of the chopper 104X is obtained from the two light receiving elements of the photo-interrupter 106X. Are formed. In this way, a two-phase pulse signal is obtained from the photointerrupter 106X, one of which is set to the XA phase and the other to the XA phase. The same applies to the photo interrupter 106Y, and the chopper 1
By the rotation of 04Y, YA-phase and YB-phase pulse signals having a phase difference of 90 ° are obtained.

Now, assume that the rotation direction of the ball 109 for rotating only the rotating body 101X is the X direction,
Assuming that the rotation direction of the ball 109 that rotates only 1Y is the Y direction, when the ball 109 is rotated in an arbitrary direction in the rotation direction, this rotation includes a rotation component in the X direction and a rotation component in the Y direction. The photo interrupter 106X detects the rotation component in the X direction, and the photo interrupter 106Y detects the rotation component in the Y direction.
The number of pulses of the XA and XB phase pulse signals from the photo interrupter 106X is proportional to the amount of rotation of the ball 109 in the X direction, and the YA and Y phases from the photo interrupter 106Y.
The number of pulses of the B-phase pulse signal is proportional to the amount of rotation of the ball 109 in the Y direction. Therefore, the XA-phase and XB-phase pulse signals are counted, and a control signal of the movement amount of the cursor on the display screen in the X direction is formed from the count value.
By counting the phase and YB phase pulse signals and forming a movement amount control signal in the Y direction of the cursor from the count values, the cursor can be moved arbitrarily in accordance with the rotation of the ball 109.

Incidentally, when the rotation of the ball 109 is arbitrary, the rotation may be reversed. In order to detect this, two-phase pulse signals whose phases are different from each other by 90 ° are obtained from the photo interrupters 106X and 106Y. When the rotation of the ball 109 in the X direction is reversed, XA output from the photointerrupter 106X
Phase relationship between the XB and XB phase pulse signals is reversed,
When the rotation in the Y direction 09 is reversed, the phase relationship between the pulse signals of the YA phase and the YB phase is reversed. Therefore, XA phase, XB
By detecting the phase relationship between the phase pulse signals and the phase relationship between the YA and YB phase pulse signals, the ball 109 is detected.
Can be detected, whereby the cursor can be moved in any direction.

FIG. 6 is a block diagram showing a processing circuit system in such a coordinate input device. In the figure, the light emitting elements (FIG. 5) of the photo interrupters 106X and 106Y are LEDs.
Are used, and are driven by the LED drive control circuit 111 to emit light. The XA-phase and XB-phase pulse signals output from the photointerrupter 106X are respectively shaped by a waveform shaping circuit 112 controlled by a timing control circuit 118,
The waveform is shaped by binarization at 113 and the YA-phase and YB-phase pulse signals output from the photointerrupter 106Y are binarized by waveform shaping circuits 114 and 115 controlled by a timing control circuit 118, respectively. The waveform is shaped and supplied to the direction detection counter 116.

The direction detection counter 116 counts the XA-phase and XB-phase pulse signals for each unit time, detects the amount of rotation of the ball 109 in the X direction, forms coordinate data of the cursor, and generates these coordinate signals. Is detected in the X direction from the phase relationship of
The rotation amount and direction of the ball 109 in the Y direction are detected from the phase and YB phase pulse signals, and the coordinate data of the cursor is formed. The detection output of the direction detection counter 116 is output from the coordinate input device via the converter interface 117.

By forming the above-described coordinate input device in a small size, it can be incorporated in a keyboard. In this case, the ball of the coordinate input device is rotated with a fingertip or the like.

[0015]

By the way, in the photointerrupters 106X and 106Y shown in FIG. 6, a light emitting element which is an LED is conventionally driven continuously to emit light continuously. We propose a coordinate input device that drives these light-emitting elements intermittently so that two light-emitting elements in the same photo-interrupter emit light alternately to prevent light interference at the light-receiving elements and save power. (JP-A-3-50238). In this case, the light emitting period of each light emitting element is set sufficiently smaller than the chopping period when the choppers 104X and 104Y rotate at the maximum speed, whereby the respective photo interrupters 106X and
A sufficient two-phase pulse signal can be obtained from 106Y.

However, when the light emitting element is intermittently driven in this way, the light receiving element intermittently receives light.
The pulse signal obtained by the rising characteristic of the light receiving element is
As shown in FIG. 7, the rise is slow and the waveform becomes very blunt. By latching such a pulse signal at the light emission timing of the light emitting element, light interference from the other light emitting element is eliminated. However, if the rise of the pulse signal is slow as described above, the level of the latch output is insufficient. Not
Even if this latch output is supplied to the waveform shaping circuits 112 to 115 in FIG. 6, a desired waveform shaping may not be performed.

An object of the present invention is to provide a coordinate input device which solves such a problem, reduces power consumption in a light emitting element, and obtains a good output pulse signal from a rotation detector. .

[0018]

In order to achieve the above object, the present invention provides a rotation detector (photo interrupter) in which light emitting elements alternately emit light of different luminous intensity,
In addition, the time for each light emitting state is changed according to the amount of rotation of the ball per unit time.

[0019]

Since the light emitting element alternates between a high light intensity (bright) light emitting state and a low light intensity (dark) light emitting state, the light receiving element performs continuous light reception instead of intermittent light reception. In this case, the light receiving element is in a bias state in the light receiving state with low luminous intensity, and when light of high luminous intensity is received in this bias state, the rising characteristic of the light receiving element is improved and the rising of the obtained pulse becomes faster.

The low-luminance light may be sufficiently weak, and thus the power consumption of the light-emitting element in the low-luminance light emitting state is sufficiently small. In addition, power consumption can be reduced by changing the time taken for these light emitting states according to the rotation speed, as compared with keeping the time of the light emission state of each luminosity constant regardless of the rotation speed of the ball. .

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a coordinate input device according to the present invention, wherein 1 is a sleeve controller, and portions corresponding to those in FIG.

In FIG. 1, a photo interrupter 106
The light emitting element as shown in FIG.
The drive is controlled by the LED drive control circuit 111.
Each of these light emitting elements does not emit light completely intermittently, but alternately takes a high light intensity light emitting state and a low light intensity light emitting state.

That is, as shown in FIG. 2A, the light-emitting element intermittently emits light at a high luminous intensity as in the prior art, but does not emit light at all during this high-luminous light emission period.
Light emission of low luminous intensity is performed. That is, the light emitting element alternately repeats high-luminance light emission and low-luminance light emission, and constantly emits light.

When the light receiving element receives light from the light emitting element performing the light emitting operation, it generates a pulse signal as shown in FIG. That is, the light-emitting element always receives light from the light-emitting element, and the output signal of the light-receiving element becomes high when light of high luminous intensity is received and low when light of low luminous intensity is received.

In this case, the pulse signal rises with a certain rising characteristic and its edge is blunted. However, the light receiving element is in a state of being biased by low luminous light, and receives high luminous light in this state. Then, the rising of the pulse signal becomes steeper than in the above-described intermittent driving in which no bias is applied. As a result, the amplitude of the pulse signal increases, and the waveform shaping by the waveform shaping circuits 112 to 115 in FIG. 1 is performed well.

In FIG. 1, the LED drive control circuit 111 is controlled by the sleeve controller 1.
The sleeve controller 1 includes a direction detection counter 11
Based on the count output of 6, it is determined whether the ball is in a low-speed rotation state or a stopped state, and the LED drive control circuit 111 is controlled by setting such a state as a sleeve mode. In this sleeve mode, the driving of the light emitting elements in the photo interrupters 106X and 106Y is controlled such that the interval between the high light emission periods is sufficiently widened. Therefore, each low-luminance light emission period becomes long.

As described above, in the sleeve mode, the ratio of the high luminous period to the low luminous period is reduced, and the power consumption of the light emitting element can be further reduced. In addition, even in this sleeve mode, the light receiving element is biased with light of low luminous intensity, so that the output pulse signal of the light receiving element has a good rise and a good waveform shaping.

The light intensity of the light-emitting element having low luminous intensity can be appropriately set in consideration of the bias effect in the light-receiving element.

[0029]

As described above, according to the present invention,
While reducing the power consumption of the light emitting element of the rotation detector, the rising characteristic of the light receiving element can be improved and the rising of the output pulse signal can be made sharper, and the coordinate data of the cursor according to the rotation of the ball can be accurately calculated. Can get well.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a coordinate input device according to the present invention.

FIG. 2 is an operation explanatory diagram of the embodiment shown in FIG. 1;

FIG. 3 is an exploded perspective view showing a mechanism of the coordinate input device.

FIG. 4 is an external perspective view of a coordinate input device obtained by assembling the components of FIG. 3;

FIG. 5 is a diagram schematically showing an internal configuration of a photo interrupter in FIG. 3;

FIG. 6 is a diagram illustrating an overall configuration of a signal processing system of the coordinate input device.

FIG. 7 is a diagram showing intermittent driving of a light emitting element and output pulses of a light receiving element.

[Explanation of symbols]

 1 Sleeve controller 106X, 106Y Photo interrupter

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 3/033 G01D 5/36

Claims (2)

(57) [Claims] A rotation detector detects the rotation of a ball, generates a pulse, counts the pulse for each unit time, and forms coordinate data of a cursor based on the count value for each unit time. In the coordinate input device, the rotation detector is an optical type including a light emitting element and a light receiving element, and the light emitting element alternately takes two light emitting states having different luminous intensities. Input device. 2. The coordinate input device according to claim 1, wherein a time period in which the light is emitted varies according to an amount of rotation of the ball per unit time.