JP7417232B2 - optical keyboard - Google Patents

Description

The present invention relates to a keyboard.

Patent Document 1 describes an optical keyboard. This keyboard has a button arranged at each intersection of a row and column of optical paths arranged in a matrix, so that when the button is pressed, one of the optical paths of each row and column is blocked. Identify the pressed button by identifying the occluded row and column.
Patent Document 2 describes a release switch that can optically detect the amount of button depression. In this release switch, a line sensor with multiple light-receiving elements and a surface light emitter face each other with a stem having a through hole in between, and when the button is pressed, the stem moves and the light source, the surface light emitter, emits light. The light-receiving element where the light enters through the through-hole changes. This is used to detect the amount of button presses.
Patent Document 3 describes a switch that can optically detect the amount of button depression. In this switch, highly directional light from a light emitting element, which is a light source, is reflected by a reflecting plate and is made to enter one of the light receiving elements in a group of light receiving elements. By rotating or moving the reflector as the button is pressed, the light-receiving element on which light enters changes depending on the amount of depression. This is used to detect the amount of button presses.

Japanese Patent Application Publication No. 07-306738 Japanese Patent Application Publication No. 2010-192410 Japanese Patent Application Publication No. 2005-158586

However, when trying to detect the amount of depression of each push button on a keyboard equipped with multiple push buttons, the switches of Patent Documents 2 and 3 require a separate light source and light receiving element for each push button, resulting in high It's cost.

By applying the same mechanism as Patent Document 2 and Patent Document 3 to the keyboard of Patent Document 1, the light source and light-receiving element group are consolidated into multiple push buttons to reduce costs, and the amount of press on each push button can also be detected. It is theoretically possible to do so. That is, in the keyboard of Patent Document 1, the stem or light shielding means of Patent Document 2 or the reflecting plate or light reflecting means of Patent Document 3 is arranged at each intersection of the optical path of the row and digit, and the stem or light shielding means of Patent Document 3 is placed at each intersection of the optical path of the row and digit. It is possible to change the optical path by displacing the light receiving element, and to detect the change using a group of integrated light receiving elements. However, using such a configuration in an actual keyboard has at least the following two problems.

The first problem is that in order to construct a matrix-like optical path, it is necessary to align the light reflecting means (mirrors) with high precision (setting the positional relationship and orientation). In the keyboard of Patent Document 1, light from one light source is sent in a time-divided manner to a plurality of optical paths in a matrix of rows and digits, but a light reflecting means is used to configure the optical paths, and they are It is necessary to accurately align the light from the light source so that it reaches the light receiving element.

The second problem is that alignment errors in the optical elements that make up the optical path make it difficult to detect the amount by which the push button is pressed.
Keyboards are subject to external forces such as pressing force on push buttons, and the temperature environment is not always constant, so the structure that supports the push buttons, light source, and photodetector group, that is, the keyboard casing, etc. It is highly assumed that the structure of the structure will be distorted due to external force or thermal expansion. This distortion becomes an alignment error and changes the optical path, resulting in an error in detecting the amount of depression or inability to detect it.

The first object of the present invention is to control the operation of multiple pushbuttons by using an integrated light source and an integrated light receiving element group, without using a matrix-like optical path that requires highly accurate alignment of optical elements such as light reflecting means. An object of the present invention is to provide an optical keyboard that can optically detect the amount of press.

A second object of the present invention is to integrate a light source and a group of light-receiving elements into a plurality of pushbuttons, and to detect the amount of depression of each pushbutton even if the structure of the keyboard casing or the like is distorted. Our goal is to provide an optical keyboard that can.

A first aspect of the present invention is an optical keyboard comprising: a push button having a protrusion; and a package that houses the push button in a manner that allows the protrusion to protrude from a hole; are plural, and at least a portion of the protrusion and at least a portion of the outside of the package have different light scattering characteristics or fluorescence characteristics, and the larger the amount of depression of the push button, the more the protrusion is attached to the package. An optical keyboard is provided that has an increased protrusion from the optical keyboard.

According to this first aspect, it becomes possible to optically observe the protrusion protruding from the package based on the difference in light scattering characteristics or fluorescence characteristics between the package and the protrusion.
Furthermore, the amount of depression of each push button can be detected by observing the size of the protrusion of the protrusion from the package.
In addition, since the protrusions protrude from the package, it is possible to illuminate the protrusions of multiple push buttons with a single light source without using a matrix optical path, and to illuminate the protrusions of multiple push buttons with a single light source. Scattered light or fluorescence can now be observed using a single imaging device.
That is, without using a matrix optical path, it becomes possible to optically detect the amount of presses of each push button using a light source and a group of light receiving elements, using scattered light or fluorescence.

As a second aspect of the present invention, there is provided an optical keyboard according to the first aspect, in which a portion of the protruding portion protrudes from the package even when the push button is not depressed.

With this second aspect, the protrusion always protrudes from the package, so the protrusion can always be optically observed. Therefore, even if the relative position of the protrusion changes due to structural distortion such as deformation of the casing, the change in position can be continuously tracked. In other words, even if structural distortion occurs such as deformation of the housing, the amount of press on a push button can be optically detected using scattered light or fluorescence without losing sight of the protrusion or mistaking it for the protrusion of another push button. become able to.

As a third aspect of the present invention, in the optical keyboard according to the first aspect or the second aspect, at least a part of the protrusion and at least a part of the outside of the package have a surface that suppresses reflection of light. A keyboard is provided.

With this third aspect, it becomes possible to optically detect the amount of press on the push button using scattered light or fluorescence without being affected by reflected light from the protrusion or the package.

As a fourth aspect of the present invention, in the optical keyboard according to any one of the first to third aspects, a light source having directionality that illuminates a plurality of the protrusions and their surroundings, and an image sensor having a light receiving surface, An optical keyboard is provided that includes an imaging element that images scattered light or fluorescence emitted by at least a portion of each of the plurality of protrusions onto the light receiving surface.

According to this fourth aspect, the scattered light or fluorescence emitted by the protrusion can be imaged by the imaging element on the light-receiving surface of the image sensor. Protrusions can be observed based on differences in light scattering properties or fluorescence properties.

As a fifth aspect of the present invention, the optical keyboard according to any one of the first to fourth aspects includes a processor and a memory, and the processor is a pixel of image data stored in the memory, and Calculate the amount of press based on the metric value of a pixel set whose elements are pixels whose values have a predetermined relationship with the reference pixel value stored in the memory, and pixels that are adjacent to the reference coordinates stored in the memory. An optical keyboard is provided.

This fifth aspect allows the processor to analyze the image data and calculate the amount of press based on the metric value of the pixel set corresponding to the protrusion.
Here, the reference coordinates are the coordinates on the image data of a pixel that is known to correspond to the protrusion of a particular push button, and the reference pixel value is the coordinate on the image data of the pixel that corresponds to the protrusion on the image data. A pixel whose pixel value has a predetermined relationship with the reference pixel value can be considered to be a pixel corresponding to a protrusion.
Therefore, a pixel set whose elements are pixels whose pixel values have a predetermined relationship with the reference pixel value and which are neighboring pixels to the reference coordinates is a pixel set whose elements correspond to the protrusion of a specific push button determined by the reference coordinates. is a set of The metric value of the set increases as the amount of depression of the push button increases and the protrusion of the protrusion increases, so the amount of depression can be calculated based on it.

As a sixth aspect of the present invention, in the optical keyboard of the fifth aspect, when the pixel value of the pixel at the reference coordinates does not have a predetermined relationship with the reference pixel value, the processor An optical keyboard is provided that searches for a pixel whose pixel value is in a predetermined relationship with the reference pixel value and writes its coordinates into the memory as new reference coordinates.

With this sixth aspect, even if a pixel corresponding to the protrusion in the image data moves from the reference coordinates due to structural distortion such as deformation of the casing and the relative position of the protrusion changes, the protrusion By searching for a pixel corresponding to the reference coordinates near the reference coordinates and resetting those coordinates as the new reference coordinates, it becomes possible to continue detecting the amount of press.

According to the present invention, an optical system that can optically detect the amount of depression of multiple push buttons using a group of integrated light sources and a group of light receiving elements, without using a matrix-like optical path that requires highly accurate alignment of optical elements. A keyboard can be provided.

In addition, according to the present invention, an optical system that integrates a light source and a group of light-receiving elements into a plurality of push buttons and can detect the amount of depression of each push button even if a structure such as a keyboard casing is distorted. A keyboard can be provided.

1 is an isometric view illustrating the appearance of an optical keyboard 1 according to the present invention. FIG. FIG. 2 is a plan view illustrating the top surface of the optical keyboard 1 according to the present invention. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 3 is a sectional view taken along line BB in FIG. 2. 3 is a block diagram illustrating the configuration of an information processing section 30. FIG. FIG. 3 is a diagram showing an example of data in a table 34. FIG. 3 is a diagram showing a specific example of image data. 3 is a flowchart illustrating the operation of the processor 31 when receiving image data from the image sensor 22. FIG. FIG. 3 is a diagram showing a specific example of image data.

Embodiments of the present invention will be described below with reference to the accompanying drawings. However, in the second embodiment, components that are the same or similar to those in the first embodiment are represented by the same or similar symbols as in the first embodiment, and detailed explanations are omitted as appropriate. Further, regarding the effects obtained in the second embodiment, descriptions of those similar to those in the first embodiment will be omitted as appropriate. The drawings of each embodiment are illustrative, and the dimensions and shapes of each part are schematic, and the technical scope of the present invention should not be interpreted as being limited to the embodiments.

<First embodiment>
An optical keyboard 1 according to a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an isometric view illustrating the external appearance of the optical keyboard 1, FIG. 2 is a plan view illustrating the top surface thereof, and FIG. 3 is a sectional view taken along line AA.
The optical keyboard 1 includes a housing 2 having a top panel 4, one or more button modules 10, a press amount detection module 20, and a light source 3.

The light source 3 is a light source that irradiates the inside of the housing 2 with light. The push amount detection module 20 captures the scattered light from the protrusion 115 obtained when the light from the light source 3 illuminates the protrusion 115 of the push button 11. It is necessary to have a directivity that simultaneously illuminates the protrusion 115, preferably including the surrounding area of the protrusion 115, and to emit light that includes a wavelength band used by the press amount detection module 20 to detect the press amount. be.
Regarding the position and directivity of the light source 3, in the method of controlling the optical path by reflection or shading as in the background art, it is necessary to accurately determine the position and directivity of the light source, but in this embodiment, from the protrusion 115 It is only necessary for the scattered light of It can be determined relatively freely.
The light source 3 may emit light temporally continuously, but it may also be controlled to emit light only during a period when the image sensor 22 receives light necessary to generate image data.

The housing 2 has one or more openings 5 in its top panel 4 into which the button module 10 is inserted.
It is preferable that the housing 2 has high light-shielding properties. This is to prevent light (environmental light) from outside the housing 2 from entering the press amount detection module 20 and affecting the press amount detection process.
At least a portion of the inner surface of the housing 2 is preferably provided with a surface that suppresses reflection of light. Alternatively, it is preferable to include a surface that suppresses reflection of the irradiated light from the light source 3. This is to prevent reflected light in addition to the scattered light of the light irradiated from the light source 3 by the inner surface of the casing 2 from entering the press amount detection module 20 and affecting the press amount detection process. For example, it is preferable to apply an anti-reflection coating or a rough surface finish.

The button module 10 includes a push button 11, a package 12, and an elastic body 13, and is used by being inserted into the opening 5 of the housing 2.

The push button 11 has a push part 111, an upper limit stopper part 112, a reaction force applying part 113, a lower limit stopper part 114, and a protruding part 115.
The push-down portion 111 is a portion that can protrude from the hole in the upper surface portion 121 of the package 12. The pressing portion 111 may directly receive pressing force from a keyboard operator. Alternatively, a keycap (not shown) may be placed above the pressing part 111, and the pressing force may be indirectly received through the keycap.
The upper limit stopper portion 112 is a portion that interferes with the package 12 to define the state in which the push button 11 is raised the most.
The reaction force applying section 113 is a part that comes into contact with the elastic body 13 and transmits the elastic force from the elastic body 13 to the push button 11.
The lower limit stopper portion 114 is a portion that interferes with the package 12 to define the lowest state of the push button 11.

The protruding portion 115 is a portion that can protrude to the outside of the package 12 from a hole in the lower surface portion 123 of the package 12 when the push button 11 is pressed. It is preferable that the larger the amount by which the pushbutton 11 is pressed down by applying a pressing force to the pressing part 111 (the amount of pressing), the larger the protrusion of the protruding part 115 to the outside of the package 12 becomes.

It is preferable that at least a portion of the protruding portion 115 protrudes to the outside of the package 12 even when the push button 11 is not depressed, that is, is not depressed and the push button 11 is in the highest raised state.

Preferably, at least a portion of the protrusion 115 has a surface that suppresses reflection of light. Alternatively, it is preferable to include a surface that suppresses reflection of the irradiated light from the light source 3. This is to prevent reflected light in addition to the scattered light of the light irradiated from the light source 3 by the protrusion 115 from entering the press amount detection module 20 and thereby affecting the press amount detection process. For example, it is preferable to apply an anti-reflection coating or a rough surface finish.

At least a portion of the protruding portion 115 is configured to have different light scattering characteristics in the wavelength band of light emitted by the light source 3 from both the inside of the casing 2 and the outside portion of the package 12 exposed inside the casing 2. There is a need. This is so that in the image data output by the image sensor 22, scattered light from the protrusion 115 and scattered light from other sources can be clearly distinguished as differences in pixel values. In other words, it is preferable that the degree of difference in the light scattering characteristics is such that it can be clearly distinguished on the image data output by the image sensor 22.
For example, when the wavelength band of the light source 3 is visible light, the protrusion 115 may be white, and the inside of the casing 2 and the outside of the package 12 may be black. Alternatively, the protrusion 115 may be made black, and the inside of the casing 2 and the outside of the package 12 may be made white.
In addition, the color of the protruding portion 115 is arbitrarily determined, and one or more colors that are significantly different from the predetermined color in one or more of brightness, saturation, and hue (that is, can be clearly distinguished on the image data) are selected. Therefore, it may be used inside the casing 2 and outside the package 12. When the light source 3 uses a wavelength band other than visible light, the protrusion 115, the inside of the casing 2, and the outside of the package 12 may have different scattering characteristics in the wavelength band.

Another way to change the scattering characteristics is to change the polarization. For example, the scattered light from the protrusion 115 may be vertically polarized, and the scattered light from the inside of the casing 2 and the outside of the package 12 may be horizontally polarized. As a method for polarizing the scattered light, for example, the surface of the protrusion 115 may be covered with a film-like polarizing filter.

The package 12 has an upper surface section 121, a side surface section 122, and a lower surface section 123, and accommodates the push button 11 so that a portion of the push button 11 projects outside and is movable up and down, and also accommodates the elastic body 13.
A hole is opened in the upper surface part 121, and the push part 111 of the push button 11 protrudes from the hole. The upper surface portion 121 also serves as a stopper when the button module 10 is inserted into the opening 5 by coming into contact with the upper surface panel 4 of the housing 2, and is also a portion that transmits the pressing force to the push button 11 to the housing 2. be.
The side portion 122 has a locking piece 124, which locks the button module 10 inserted into the opening 5 so that it does not come off.
A hole is formed in the lower surface portion 123, and the protruding portion 115 of the push button 11 protrudes from the hole. The lower surface portion 123 also contacts and supports the elastic body 13, thereby applying a reaction force to the push button 11 when the push button 11 is pressed down via the elastic body 13.

The package 12 has light-shielding properties to prevent ambient light from outside the optical keyboard 1 from entering the housing 2 via the button module 10 and affecting the press amount detection processing by the press amount detection module 20. Preferably high. For this reason, it is preferable that the shape is such that the entire surface is covered with minimal gaps except for the upper and lower holes through which the push button 11 projects. Further, it is preferable to use a material with high light-shielding properties.
Further, for the same reason as the protrusion 115, it is preferable that at least a portion of the outer portion of the package 12 exposed inside the housing 2 has a surface that suppresses reflection of light. Alternatively, it is preferable to include a surface that suppresses reflection of the irradiated light from the light source 3.

The elastic body 13 contacts the push button 11 and the package 12, and applies an elastic restoring force to the push button 11 according to the amount of push of the push button 11 as a reaction force against the push force. As the elastic body 13, a coil spring or rubber may be used. Alternatively, magnetic force such as a magnet may be used to perform the same function.

Note that although the drawing shows that one button module 10 accommodates one push button 11 and one elastic body 13 in one package 12, it is possible to accommodate a plurality of push buttons 11 and a plurality of elastic bodies in one package 12. It may be configured to accommodate 13.

Next, the press amount detection module 20 will be explained with reference to FIG. FIG. 4 is a sectional view of the optical keyboard 1 taken along the line B-B. The press amount detection module 20 includes an imaging element 21, an imaging element 22, and an information processing section 30.

The imaging element 21 is an optical element that images scattered light emitted by at least a portion of what is inside the housing 2, such as the inner surface of the housing 2 or the button module 10, on the light receiving surface 23. The imaging element 21 needs to image the light from at least a portion of each of the plurality of protrusions 115 on the light receiving surface 23. In the imaging element 21, light from one point inside the housing 2 reaches approximately the same location on the light-receiving surface 23, and light from two sufficiently distant points inside the housing 2 reaches substantially the same location on the light-receiving surface 23. It is preferable that it be something that can be delivered to the desired location. As the imaging element 21, a lens, a pinhole, or a concave mirror may be used.

The image sensor 22 has a light receiving surface 23 that receives incident light, and is an element that outputs image data corresponding to the intensity distribution of the incident light on the light receiving surface 23. The image sensor 22 repeatedly receives incident light and outputs image data corresponding to its intensity distribution. The time period of the repetition may be constant, but the period may be changed depending on the degree of change in the image data, for example. As the image sensor 22, a charge coupled device (CCD) image sensor or a CMOS image sensor may be used.
The image data is configured to include a set of values for each pixel corresponding to a minute area on the light receiving surface 23, and the value of a pixel corresponds to the received light intensity of the minute area on the light receiving surface 23 to which that pixel corresponds. The pixel value may be a scalar value representing the received light intensity of a single wavelength band, or a vector value that bundles the received light intensity of each of a plurality of wavelength bands.
A filter 24 may be provided in front of the light receiving surface 23 to weaken part of the light incident on the light receiving surface 23. The filter 24 may weaken a part of the wavelength band of the light incident on the light receiving surface 23, for example. Further, the polarization of a part of the light incident on the light receiving surface 23 may be weakened.

The information processing section 30 will be explained with reference to FIG. FIG. 5 is a block diagram illustrating the configuration of the information processing section 30. The information processing unit 30 includes a processor 31 that processes data according to a program 33, and a memory 32 that stores the program 33 in a readable manner and stores data such as a table 34 in a readable and writable manner. The program 33 controls the operation of the processor 31 and causes the processor 31 to perform a press amount detection process of detecting the press amount of the push button 11 in response to the image data generated by the image sensor 22.

Before explaining the press amount detection process by the processor 31, the evaluation value calculation process, which is a partial process thereof, will be explained. The evaluation value calculation process is a process of outputting an evaluation value from input of image data, reference coordinates, and reference pixel values. More specifically, for a pixel set whose elements are pixels whose pixel values have a predetermined relationship with the input reference pixel value in the input image data, and pixels that are neighboring to the input reference coordinates, the set is This is the process of calculating the measured value of and outputting it as an evaluation value.
It is assumed that this evaluation value becomes a larger value as the input image data corresponds to a larger pressing amount of the push button 11. That is, as the amount of depression of the push button 11 increases, the protrusion of the protrusion 115 from the package 12 becomes larger, so the area of the light receiving surface 23 that receives the scattered light from the protrusion 115 through the imaging element 21 also becomes larger. Therefore, the image data output by the image sensor 22 at that time also shows pixel values specific to the scattered light from the protrusion 115 in more pixels. The evaluation value calculation process should just capture this and output a larger evaluation value.

The reference coordinates and reference pixel values that are input to the evaluation value calculation process are values unique to each of the plurality of push buttons 11 provided on the optical keyboard 1. The reference coordinates are the coordinates in the image data where a specific pixel value appears in the scattered light from the protrusion 115 of a particular push button 11, and the reference pixel value is that specific pixel value.

In the evaluation value calculation process, a predetermined relationship with a reference pixel value means that a certain pixel value satisfies a predetermined relationship when compared with the reference pixel value. For example, when the pixel value is a scalar value, it may match the reference pixel value within a certain error range. Alternatively, the pixel value may be greater than the reference pixel value. Alternatively, it may be smaller than the reference pixel value. If the pixel value is a vector value, it may be converted into a scalar using a norm and used as a match or a magnitude relationship within that error range, or it may be converted into a scalar using a scalar product with a predetermined vector and used as a match or a size relationship within that error range. .

In the evaluation value calculation process, pixels that are near the reference coordinates may be, for example, pixels whose coordinates are within a predetermined distance from the reference coordinates. As another example, pixels that can be reached starting from a pixel at the reference coordinates only through pixels whose pixel values have a predetermined relationship with the reference pixel values may be defined as neighbors of the reference coordinates. The reference coordinate pixel itself may also be included.

In the evaluation value calculation process, the metric value of a pixel set may be, for example, the number of pixels included in the set. As another example, it may be the maximum distance between any two pixels included in the set.

Next, the table 34 stored in the memory 32 will be explained with reference to FIG. The table 34 is data having one or more push button data including reference coordinates, reference pixel values, minimum values, maximum values, and codes. An example of the data structure and data of the table 34 is shown in FIG. In the example shown in Figure 6, the data structure is in a tabular format, and the standard coordinates, standard pixel value, minimum value, maximum value, and code of the push button data are each expressed as columns in the table, and each of the four push button data is represented in the table. It is expressed as a line.

The push button data is as follows for a specific push button 11, using image data when the push button 11 is not pressed and image data when the push button 11 is pressed to the maximum. This is required data.
The reference coordinates are the coordinates of a pixel that captures the scattered light from the protrusion 115 in the image data when the push button 11 is not pressed. If there are multiple pixels, the coordinates of one of them shall be used.
The reference pixel value is the pixel value of the pixel at the reference coordinates in the image data when the push button 11 is not pressed.
The minimum value is an evaluation value calculated by inputting the image data when the push button 11 is not pressed, the reference coordinates, and the reference pixel value into the evaluation value calculation process described above.
The maximum value is an evaluation value calculated by inputting the image data when the push button 11 is pressed to the maximum, the reference coordinates, and the reference pixel value into the evaluation value calculation process described above.
The code is a number or character string uniquely assigned to the push button 11.

The relationship between reference coordinates, reference pixel values, and minimum and maximum values will be explained using a specific example. FIG. 7 is a diagram representing an example of image data. FIG. 7(a) is an example of image data when the push button 11 is not pressed, and FIG. 7(b) is an example of image data when the push button 11 is pressed to the maximum. Each square of a grid of 10 squares in the horizontal axis (X-axis) direction and 10 squares in the vertical axis (Y-axis) direction represents a pixel, and the value within the square represents the pixel value. Although scalar values are used as pixel values in this example, vector values such as RGB values may also be used. The serial numbers assigned to the X and Y axes represent the coordinates of each axis. If we represent the position 5 on the X axis and 2 on the Y axis as (5,2), then in the image data of Figure 7(a), the pixel value of the pixel at coordinates (5,2) is 1. .

Note that since the image data needs to include pixels corresponding to each of the protrusions 115 of the plurality of button modules 10 included in the optical keyboard 1, the number of pixels is required to be larger than 10 pixels in the vertical and horizontal directions. It should be noted that FIG. 7 shows only a portion of the image data, a pixel corresponding to one protrusion 115, and its surrounding pixels in order to explain the invention in an easy-to-understand manner. This is the same in all subsequent drawings showing image data.

In FIG. 7, the reference coordinates are the coordinates of the pixel that captures the scattered light from the protrusion 115 in the image data when the push button 11 is not pressed, that is, the image data in FIG. 7(a). Assume that the coordinates are (4,3). In Figure 7(a), the square at the coordinates (4,3) is shown in reverse black and white, but this is a convenient notation to indicate that the coordinates are the reference coordinates, and the same applies in subsequent drawings. shall be.
The reference pixel value is the pixel value of the pixel at the reference coordinates in the image data when the push button 11 is not pressed, so the pixel value of the pixel at the coordinates (4,3) of the image data in FIG. 7(a) is 5. It is.

The minimum value is an evaluation value calculated by inputting the image data when the push button 11 is not pressed, the reference coordinates, and the reference pixel value into the evaluation value calculation process described above. In the evaluation value calculation process, for a pixel set whose elements are pixels whose pixel values have a predetermined relationship with the reference pixel value and whose elements are pixels that are near the reference coordinates, the metric value of the set is calculated and used as the evaluation value. As an example, the pixel value has a predetermined relationship with the reference pixel value when the pixel value matches the reference pixel value within an error range of plus or minus 1, and is in the vicinity of the reference coordinates. A pixel is a pixel that can be reached starting from a pixel at the reference coordinates only through pixels whose pixel values have a predetermined relationship with the reference pixel value, and the metric value of a pixel set is the number of pixels included in the set. shall be.
Then, "a pixel set whose elements are pixels whose pixel values have a predetermined relationship with the reference pixel value, and which are adjacent to the reference coordinates" means coordinates (3,3), (5,3), This is a set of pixels (4,4) and (5,4). The minimum value is the metric value of this pixel set, ie the number of pixels, ie 4.

The maximum value is an evaluation value calculated by inputting the image data when the push button 11 is pressed to the maximum, the reference coordinates, and the reference pixel value into the evaluation value calculation process described above. Assuming that the evaluation value calculation process is the same as that for the minimum value above, what is "a pixel set whose elements are pixels whose pixel values have a predetermined relationship with the reference pixel value and which are neighboring pixels of the reference coordinates"? That is, the coordinates (3,3), (5,3), (4,4), (5,4), (6,4), (5,5), (6,5), (6,6) It is a collection of pixels. The maximum value is the metric value of this pixel set, ie 8.

Next, with reference to FIG. 8, the operation of the press amount detection process by the processor 31 controlled by the program 33 will be described. FIG. 8 is a flowchart illustrating the operation of the processor 31 when image data is input from the image sensor 22.
When the processor 31 receives image data, it stores the image data in the memory 32 (S1).
Next, the processor 31 sets the first row of the table 34 stored in the memory 32 as the row to be processed (S2).
Next, the processor 31 reads the row to be processed in the table 34 and obtains the reference coordinates, reference pixel value, minimum value, maximum value, and code (S3).
Next, the processor 31 reads the pixel value of the pixel at the reference coordinates of the image data stored in the memory 32, checks whether it has a predetermined relationship with the reference pixel value (S4), and if it has the predetermined relationship, proceeds to step S6. , otherwise proceed to step S5.
Note that the predetermined relationship with the reference pixel value means the same relationship as that in the evaluation value calculation process, and the same meaning applies to the next step S5.

If the process proceeds to step S5, the processor 31 searches for pixels whose pixel values have a predetermined relationship with the reference pixel value in the vicinity of the reference coordinates of the image data stored in the memory 32, and converts the coordinates of the found pixel into new reference coordinates. is written in the reference coordinate column of the processing target row of the table 34 (S5), and the process proceeds to step S3.
When proceeding to step S6, the processor 31 calculates the evaluation value by inputting the image data stored in the memory 32, the reference coordinates, and the reference pixel value to the evaluation value calculation process (S6).
Next, the processor 31 outputs the press amount index calculated by the following formula along with the code (S7).
Pressing amount index = (evaluation value - minimum value) / (maximum value - minimum value)
This press amount index is an index representing the press amount of the push button 11, which is normalized so that it becomes 0 when the push button 11 is not pressed and becomes 1 when it is pressed to the maximum.

Next, the processor 31 checks whether the row to be processed is the last row of the table 34 (S8), and if it is the last row, the process ends; otherwise, the process proceeds to step S9.
When proceeding to step S9, the processor 31 sets the next row of the table 34 to be processed as a new line to be processed (S9), and proceeds to step S3.

Next, a specific example of the operation of the press amount detection process will be described. In this example, consider a case where the data in FIG. 6 is stored in the memory 32 as the data in the table 34, and the image data shown in FIG. 9(a) is input to the processor 31.
Also in this specific example, a pixel value having a predetermined relationship with a reference pixel value means that the pixel value matches the reference pixel value within an error range of plus or minus 1, and pixels that are near the reference coordinates are defined as Starting from a pixel of coordinates, a pixel can be reached only through pixels whose pixel values have a predetermined relationship with a reference pixel value, and the metric value of a pixel set is the number of pixels included in the set.

First, in step S1, the processor 31 stores input image data in the memory 32.
Next, in step S2, the processor 31 sets the first row of the table 34 stored in the memory 32 as the row to be processed.
Next, in step S3, the processor 31 reads the row to be processed in the table 34 and obtains the reference coordinates, reference pixel value, minimum value, maximum value, and code. In this case, reference coordinates = (4,3), reference pixel value = 5, minimum value = 4, maximum value = 8, and code = 0x41.
Next, in step S4, the processor 31 reads out the pixel value of the pixel at the reference coordinates of the image data stored in the memory 32, and checks whether it has a predetermined relationship with the reference pixel value. In this case, the pixel value at the reference coordinates (4,3) is 1, which is not in a predetermined relationship with the reference pixel value (=5). Therefore, the process next proceeds to step S5.
Next, in step S5, the processor 31 searches for a pixel whose pixel value has a predetermined relationship with the reference pixel value in the vicinity of the reference coordinates of the image data stored in the memory 32. A pixel near the reference coordinates (4,3) whose pixel value has a default relationship with the reference pixel value (=5) is the pixel at the coordinates (4,4) (pixel value = 4), so this In the example, that pixel is adopted, the coordinates of that pixel are written in the reference coordinate column of the processing target row of the table 34, and the process proceeds to step S3.
The reference coordinates are expressed as black-and-white inverted squares in FIG. 9. Before the process in step S5, the black-and-white inverted square in FIG. The reference coordinates will change to the black and white inverted square in 9(b).

Next, in step S3, the processor 31 reads the row to be processed in the table 34 and obtains the reference coordinates, reference pixel value, minimum value, maximum value, and code. The reference coordinates are different from before: reference coordinates = (4,4), reference pixel value = 5, minimum value = 4, maximum value = 8, code = 0x41.
Next, in step S4, the processor 31 reads out the pixel value of the pixel at the reference coordinates of the image data stored in the memory 32, and checks whether it has a predetermined relationship with the reference pixel value. In this case, the pixel value of the reference coordinates (4,4) is 4, which has a predetermined relationship with the reference pixel value (=5). Therefore, the process next proceeds to step S6.
Next, in step S6, the processor 31 calculates an evaluation value by inputting the image data stored in the memory 32, the reference coordinates, and the reference pixel value to the evaluation value calculation process. In this case, the evaluation value will be 5.
Next, in step S7, the processor 31 calculates a press amount index. The press amount index is (5 - 4) / (8 - 4) = 0.25
becomes. Then, the press amount index (=0.25) is output together with the code (=0x41).

Next, in step S8, the processor 31 checks whether the row to be processed is the last row of the table 34, but since the row to be processed is not the last row, the process advances to step S9.
Next, in step S9, the processor 31 sets the next row of the table 34 to be processed, that is, the second row, as a new row to be processed, and proceeds to step S3.
Although a description of subsequent operations will be omitted, similar processing is performed for all remaining rows of the table 34.

In this way, in the press amount detection process, if the pixel value of the pixel at the reference coordinates does not have a predetermined relationship with the reference pixel value in the processes of steps S4 and S5, the reference coordinates are moved to the coordinates of a nearby appropriate pixel. Such a case may also occur when the housing 2 is distorted due to the pressing force on the push button 11 or thermal expansion.
In other words, the previous image data from the image sensor 22 captures the scattered light from the protrusion 115, and the pixel at the reference coordinates that had a pixel value in a predetermined relationship with the reference pixel value does not appear in the next image data. Due to the distortion of the housing 2, the positional relationship between the image sensor 22, the image forming element 21, and the protrusion 115 changes, and the scattered light from the protrusion 115 is no longer captured, and the pixel value shows a predetermined relationship with the reference pixel value. It may happen that it disappears.
Even in that case, unless the distortion of the housing 2 is large and occurs in a short period of time based on the time interval at which the image sensor 22 outputs image data, the change from the previous image data can be expected to be small. Therefore, it can be expected that the pixel that captures the scattered light from the protrusion 115 is located near the reference coordinates, and through the processing in steps S4 and S5, that pixel can be found and the reference coordinates can be moved to that pixel. In other words, even if the pixel that captures the scattered light from the protrusion 115 moves on the image data, it is tracked and set to the reference coordinates through the processing in steps S4 and S5. Therefore, even if such distortion occurs, the amount of depression of the push button 11 can be detected.

In order to track the pixels that capture the scattered light from the protrusions 115, there must always be pixels in the image data that capture the scattered light from the protrusions 115. That is, there needs to be a pixel that captures the scattered light from the protrusion 115 not only when the push button 11 is pressed, but also when it is not pressed. Therefore, as described above, it is preferable that at least a portion of the protruding portion 115 protrudes to the outside of the package 12 even when the push button 11 is not depressed.

<Second embodiment>
An optical keyboard 1 according to a second embodiment of the present invention will be explained focusing on the differences from the first embodiment. In the first embodiment, using image data generated by the image sensor 22, the difference between the characteristics of the light scattered by the protrusion 115 of the light irradiated by the light source 3 and the characteristics of the scattered light from other parts is expressed as a difference in pixel values. However, in the second embodiment, image data generated by the image sensor 22 is used to identify the difference between the characteristics of the fluorescence from the protrusion 115 excited by the irradiation light from the light source 3 and the characteristics of the fluorescence from other parts. Identification as differences in pixel values.

Therefore, for at least a portion of the protruding portion 115, the characteristics of the fluorescence emitted when receiving the light emitted by the light source 3 are different from those of the inside of the casing 2 and the outside portion of the package 12 exposed inside the casing 2. It is necessary to make it different from the characteristics.
For example, the protrusion 115 is formed using a fluorescent material that absorbs light in an excitation wavelength band and emits light in a fluorescence wavelength band different from the excitation wavelength band, and The fluorescent material may be used in a relatively small amount or may not be used. As another example, a fluorescent material having different fluorescence wavelength bands may be used for the protrusion 115, the inside of the casing 2, and the outside of the package 12. As yet another example, the polarization of fluorescence may be different between the protrusion 115, the inside of the casing 2, and the outside of the package 12.

The light source 3 needs to emit light that includes the excitation wavelength band. Further, it is preferable that the light source 3 does not emit light in the fluorescence wavelength band of the protrusion 115. It is preferable to provide a filter 24 in front of the light receiving surface 23 of the image sensor 22 that weakens a portion of the light incident on the light receiving surface 23 other than the fluorescence wavelength band of the protrusion 115.

In addition, in the first embodiment, at least a portion of the protruding portion 115, both the inside of the casing 2 and the outside portion of the package 12 exposed inside the casing 2, emit light in the wavelength band of the light emitted by the light source 3. Although it was mentioned that it is necessary to have different scattering characteristics, this is not necessary in the second embodiment.
Furthermore, in the first embodiment, the light source 3 needs to emit light that includes the wavelength band used by the press amount detection module 20 to detect the press amount, but in the second embodiment, this is not necessary.
In addition, the portion described as "scattered light" in the first embodiment may be read as "fluorescence".

1 optical keyboard
2 Housing
3 light source
4 Top panel
5 opening
10 button module
11 push button
111 Press down part
115 Protrusion
12 packages
13 Elastic body
20 Press amount detection module
21 Imaging element
22 Image sensor
23 Photosensitive surface
24 filter
30 Information processing department
31 processor
32 memory
33 programs
34 table

Claims (5)

An optical keyboard comprising: a push button having a protrusion; and a package housing the push button in such a manner that the protrusion can be protruded from a hole;
The push buttons are plural;
At least a portion of the protrusion and at least a portion of the outside of the package have different light scattering characteristics or fluorescence characteristics,
The greater the amount of depression of the push button, the greater the protrusion of the protrusion from the package ;
at least a portion of the protrusion and at least a portion of the outer side of the package include a surface that suppresses reflection of light;
optical keyboard. The optical keyboard according to claim 1, wherein a portion of the protruding portion protrudes from the package even when the push button is not depressed. a light source with directivity that illuminates the plurality of protrusions and their surroundings;
an image sensor including a light-receiving surface;
The optical keyboard according to claim 1 or 2 , further comprising an imaging element that images scattered light or fluorescence emitted by at least a portion of each of the plurality of protrusions on the light receiving surface. An optical keyboard comprising: a push button having a protrusion; and a package housing the push button in such a manner that the protrusion can be protruded from a hole;
The push buttons are plural;
At least a portion of the protrusion and at least a portion of the outside of the package have different light scattering characteristics or fluorescence characteristics,
The greater the amount of depression of the push button, the greater the protrusion of the protrusion from the package;
a processor and a memory, the processor is a pixel of image data stored in the memory, and the pixel value has a predetermined relationship with a reference pixel value stored in the memory, and the processor is a pixel of image data stored in the memory; An optical keyboard that calculates the amount of press based on the metric value of a pixel set whose elements are pixels that are neighboring to the reference coordinates to be stored. If the pixel value of the pixel at the reference coordinates does not have a predetermined relationship with the reference pixel value, the processor selects a pixel in the vicinity of the reference coordinates of the image data whose pixel value has a predetermined relationship with the reference pixel value. The optical keyboard according to claim 4 , wherein the coordinates are searched for and written into the memory as new reference coordinates.

Images