JP4060124B2 - Imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus such as a video camera, an in-vehicle camera, and a surveillance camera using a solid-state imaging device such as a CCD imaging device or a CMOS imaging device.
[0002]
[Prior art]
In recent years, imaging devices using solid-state imaging devices such as CCD imaging devices and CMOS imaging devices have been commercialized as imaging devices. In these imaging apparatuses, generally, a video signal output from a solid-state imaging device is appropriately converted and corrected so that it can be used externally by a video signal processing circuit, and output as a digital or analog video signal. At the same time, the video signal processing circuit discriminates brightness and color based on a signal input from the solid-state image sensor, and controls iris and white balance.
[0003]
When these conversion, correction, and control are performed in the video signal processing circuit, signal variations among individuals occur due to variations in image pickup devices and other components. Therefore, in order to suppress variations inherent in the apparatus and to suit the user's application and purpose, the set values of the video signal processing circuit are adjusted during production. This adjustment result is generally stored as setting information in a rewritable nonvolatile memory.
[0004]
When the apparatus is activated, the setting information adjusted and written at the time of production is read from the nonvolatile memory, and settings are made in the video signal processing circuit. Thereby, there is little variation between apparatuses, and a video signal suitable for the user's purpose and purpose can be obtained.
[0005]
Next, the relationship between general video signal processing circuit setting information and data stored in the nonvolatile memory will be described. A number (address) for distinguishing each is assigned to an internal setting portion of the video signal processing circuit, and a setting value is input as setting information to each address. When storing the setting values in the nonvolatile memory, the setting values are written in the nonvolatile memory in the order of addresses assigned to the setting values, for example, in ascending order.
[0006]
Then, when setting a setting value in the video signal processing circuit at the time of startup or the like, the setting value is read from the nonvolatile memory, and the read value is set in the internal setting portion of the video signal processing circuit in the address order, for example, ascending order. In this way, the settings at the time of adjustment can be reproduced.
[0007]
[Problems to be solved by the invention]
However, conventionally, a nonvolatile memory having a capacity equal to or larger than the number of set values of the video signal processing circuit is used even if it is not necessary to store all set values. In recent years, the number of set values of the video signal processing circuit tends to increase as the functionality of the video signal processing circuit increases. This requires a large-capacity memory and directly leads to an increase in cost.
[0008]
In addition, an increase in the setting value of the video signal processing circuit leads to an increase in the time for reading and setting the nonvolatile memory at the time of startup or the like, which causes a decrease in system performance.
[0009]
In addition, because the setting values of the video signal processing circuit are written in the nonvolatile memory as they are in the address order, if other people analyze the values written in the nonvolatile memory, know-how such as adjustment contents and methods can be easily stolen. There is.
[0010]
In view of the above, the present invention provides an imaging device that can suppress the capacity and startup time of a nonvolatile memory used at startup and makes it difficult to steal know-how by making analysis of setting contents difficult With the goal.
[0011]
[Means for Solving the Problems]
The problem solving means according to the present invention includes a processing means for processing a video signal from an image sensor, a setting means for setting a plurality of internal information necessary for the operation of the processing means at startup, and internal information to be set. Storage means for storing, and the storage means stores apparatus-specific setting information necessary at the time of activation among the internal information. The setting information is an adjustment value for suppressing variations inherent in the apparatus during production, or a setting value different from an initial value held in advance by the setting means.
[0012]
That is, the internal information other than the setting information among the internal information is information common to each device and is fixed as an initial value. Therefore, it is not necessary to store in the storage means. As a result, information to be stored in the storage means is reduced, and a storage means with a small capacity can be used. In addition, since the information read from the storage means is reduced, the time required for reading and the time required for setting are reduced, and the activation time can be shortened accordingly.
[0013]
And the identification information which shows the necessity of the setting at the time of starting with respect to each internal information is memorize | stored in a memory | storage means. The identification information corresponds to all internal information on a one-to-one basis. This identification information and setting information are stored in combination. That is, a predetermined number of identification information and setting information that is required to be set corresponding to the identification information are stored in this order, and are repeated until it corresponds to all internal information. For example, a plurality of pieces of identification information are stored, and then the setting information required to be set by these pieces of identification information is stored. Repeat this. Or only the identification information with respect to all the internal information is memorize | stored previously, and the setting information made into the setting necessity next is memorize | stored sequentially. By storing information having different contents in a mixed manner in this way, the stored contents can be made difficult to understand, and security is improved.
[0014]
Further, it is preferable to provide check means for checking whether the setting information from the storage means is set normally. When the setting cannot be performed normally, the setting means sets the initial information held in advance. As a result, even if it cannot be set correctly due to some abnormality, it is possible to ensure a minimum function for operation.
[0015]
As the checking means, the marker information is stored in a specific area in the storage area of the storage means, and it is checked whether or not the marker information read out during the setting is correct. By confirming correct marker information, it is determined that the marker has been set normally. If the marker information cannot be confirmed correctly, it is determined that it cannot be set normally. Thereby, the reliability at the time of setting can be improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An imaging apparatus as a video camera according to an embodiment of the present invention is shown in FIG. In FIG. 1, reference numeral 1 denotes an image sensor that converts an image from a subject into an electrical signal. Reference numeral 2 denotes a TG circuit that generates a timing signal necessary for driving the image sensor 1. Reference numeral 3 denotes a CDS / AGC circuit that performs correlated double sampling on the video signal from the image sensor 1 and amplifies it. Reference numeral 4 denotes an A / D conversion circuit that converts an analog signal output from the CDS / AGC circuit 3 into a digital signal. Reference numeral 5 denotes a luminance / color signal generation circuit that generates a luminance signal and a color signal based on a signal output from the A / D conversion circuit 4. A gamma correction circuit 6 performs gamma correction on the luminance signal created by the luminance / color signal creation circuit 5. Reference numeral 7 denotes a white balance adjustment circuit that performs white balance adjustment on the color signal created by the luminance / color signal creation circuit 5. A matrix correction circuit 8 adjusts the hue of the color signal from the white balance adjustment circuit 7. Reference numeral 9 denotes a luminance / color signal synthesis circuit for synthesizing the luminance signal from the gamma correction circuit 6 and the color signal from the matrix correction circuit 8 to create a video signal. A D / A conversion circuit 10 converts the digital video signal from the luminance / color signal synthesis circuit 9 into an analog video signal. A control microcomputer 11 controls the white balance adjustment circuit 7, the TG circuit 2, and the CDS / AGC circuit 3, and performs iris and automatic white balance control. These circuits constitute processing means (video signal processing circuit).
[0017]
A register circuit 12 stores coefficients for operating the control microcomputer 11, the white balance adjustment circuit 7, the matrix correction circuit 8, the luminance / color signal generation circuit 5, the gamma correction circuit 6, and the luminance / color signal synthesis circuit 9. It is. Reference numeral 13 denotes an initial operation of the control microcomputer 11, the white balance adjustment circuit 7, the matrix correction circuit 8, the luminance / color signal generation circuit 5, the gamma correction circuit 6, and the luminance / color signal synthesis circuit 9 when the video camera is activated. 2 is an EEPROM as a storage means for storing a coefficient necessary for performing the operation. These coefficients are adjusted and written during production of the video camera. Reference numeral 14 denotes an EEPROM reading circuit that reads data from the EEPROM 13 and sets the register circuit 12 at startup. The register circuit 12 and the EEPROM read circuit 14 constitute setting means for setting internal information necessary for the operation of the processing means at startup.
[0018]
15 reads out the data from the EEPROM 13 at the time of start-up and compares the head marker data written in the head address (head area) of the EEPROM 13 with the head marker data incorporated in advance before setting in the register circuit 12. It is a head marker comparison circuit for determining whether or not they match. 16 reads all data from the EEPROM 13 at the time of start-up, and after the setting in the register circuit 12 is completed, the end marker data written in the final address (end area) of the EEPROM 13 is compared with the built-in end marker data. And an end marker comparison circuit for determining whether or not they match. The head marker comparison circuit 15 and the end marker comparison circuit 16 constitute check means for checking the marker information (marker data) and checking whether it has been set normally.
[0019]
Next, normal operation of the video camera will be described. In FIG. 1, an electrical signal obtained by converting an image of a subject by the image sensor 1 is subjected to correlated double sampling by the CDS / AGC circuit 3 and gain is applied by control from the control microcomputer 11.
[0020]
The correlated double sampled video signal is converted into a digital signal by the A / D conversion circuit 4 and input to the luminance / color signal generation circuit 5. In the luminance / color signal generation circuit 5, a luminance signal is generated by adding the signals of adjacent pixels and input to the gamma correction circuit 6. The gamma correction circuit 6 performs an optimum gamma correction for displaying the luminance signal on a display device such as a cathode ray tube and inputs the luminance signal to the luminance / color signal synthesis circuit 9.
[0021]
In addition, the luminance / color signal generation circuit 5 calculates a color difference signal (RY signal, BY signal) from the signal separated for each color filter and inputs it to the white balance adjustment circuit 7. The white balance adjustment circuit 7 measures the balance between red and blue from the control microcomputer 11 and performs gain adjustment so that white balance can be obtained. The signal adjusted by the white balance adjustment circuit 8 is input to the matrix correction circuit 8 to adjust the hue.
[0022]
The luminance signal output from the gamma correction circuit 6 and the color signal corrected by the matrix correction circuit 8 are combined by the luminance / color signal combining circuit 9, and a synchronizing video signal is added to create a digital video signal. The digital video signal synthesized by the luminance / color signal synthesis circuit 9 is converted into an analog video signal by the D / A conversion circuit 10 and outputted to the outside.
[0023]
In addition, the control microcomputer 11 always measures the luminance level and color balance of the signal and adjusts the electronic shutter of the image sensor 1 and the gain of the CDS / AGC circuit 3. Adjustments are made so that the image has a constant brightness, and white balance is controlled to optimize the color.
[0024]
Here, a detailed description will be given of the startup operation of the video camera. First, FIG. 2 shows register numbers and functions determined in the register circuit 12, initial values held in advance by the register circuit 12, and set values to be actually set.
[0025]
As shown in FIG. 2, the register circuit 12 has a total of 32 registers, register numbers 00 to 31. The bit length of each register is 8 bits, and a value from 0 to 255 can be set.
[0026]
Each register is assigned a function of each circuit in the video signal processing circuit, and is used in the white balance adjustment circuit 7 (register numbers 00 and 01) and used in the matrix correction circuit 8 (register number 02). To 05), used in the luminance / color signal generation circuit 5 (register numbers 06 to 08), used in the gamma correction circuit 6 (register numbers 09 and 10), and used in the luminance / color signal synthesis circuit 9 (Register numbers 11 and 12), those used by the control microcomputer 11 for iris control and white balance control (register numbers 13 to 16), and those used by the control microcomputer 11 as a work area (register numbers 17 to 31) ).
[0027]
Each register has an initial value in the circuit in advance. By setting these initial values, a certain amount of operation can be performed without reading the set values from the EEPROM 13.
[0028]
Here, of the registers of the register circuit 12, which register number information is stored in the EEPROM 13 is determined whether or not the video camera needs a set value of the register at the time of activation. Decided by whether or not. In other words, the setting value that is setting information to be stored in the EEPROM 13 is a value adjusted to suppress variations inherent in the apparatus during production, or a setting value that does not change during operation of the apparatus, that is, the apparatus during production. Among the setting values that are not different from each other and do not change during operation, the setting values are different from the initial values. Since these setting values are different from the initial values, they need to be set at the time of activation and are written in the EEPROM 13.
[0029]
Further, when there is no need to change the initial value that the register circuit 12 has in advance, it is not necessary to set the register. For example, in FIG. 2, the R gain and B gain of register numbers 00 and 01 are register values that need to be constantly changed when the control microcomputer 11 performs white balance control. Since this register value changes depending on what is imaged as a subject, it is not necessary to set the register value and it is not necessary to store the set value in the EEPROM 13. Since the control microcomputer 11 uses the register numbers 17 to 31 as a work area when performing various processes, it is not necessary to store these setting values in the EEPROM 13.
[0030]
When the setting value of the resist to be stored is determined as described above, the setting value is written in the EEPROM 13 while determining whether the setting is necessary for each register. Of the register numbers shown in FIG. 2, data of 02, 03, 05, 06, 09, 10, 15, 16 is written in the EEPROM 13. The writing time is at the time of production, but it may be performed before shipment.
[0031]
An example of creating data to be written in the EEPROM 13 is shown in FIG. First marker data is written to addresses 00 to 01 of the EEPROM 13. The head marker data is FFh and AAh (hexadecimal notation). A setting flag corresponding to the register numbers 00 to 07 is written in the address 02. Here, since the set values of the register numbers 02, 03, 05, and 06 are written, the value of the set flag is 6Ch (hexadecimal notation). In the addresses 03 to 06, the set values of the register numbers 02, 03, 05, and 06 are sequentially written. In the address 07, setting flags corresponding to the register numbers 08 to 15 are written. Here, since the set values of the register numbers 09, 10 and 15 are written, the value of the setting flag is 86h (hexadecimal notation). In the addresses 08 to 10, the set values of the register numbers 09, 10 and 15 are sequentially written. In the address 11, a setting flag corresponding to the register numbers 16 to 23 is written. Here, since the setting value of register number 16 is written, the value of the setting flag is 01h (hexadecimal notation). At address 12, setting data of register number 16 is written. A setting flag corresponding to the register numbers 24 to 31 is written in the address 13. Here, since there is no register to be written, the value of the setting flag is 00h (hexadecimal notation). At the addresses 14 and 15, end marker data is written. The end marker data is FFh, 55h (hexadecimal notation).
[0032]
Here, the setting flag is identification information indicating whether or not a setting value is set in the register. Then, a certain number of identification information, here, eight setting flags are written in one address, and subsequently, setting values to be set are written in order from the next address. By repeating this until all the registers are supported and writing to each address, all setting values for the registers that need to be set in the register circuit 12 are stored.
[0033]
A setting procedure when starting the video camera will be described with reference to FIG. When the power of the video camera is turned on (S1), the EEPROM reading circuit 14 first reads the head marker data written at the head address of the EEPROM 13 (S2). The head marker data is composed of 2 bytes.
[0034]
The head marker comparison circuit 15 compares the read head marker data with the head marker data preset in the head marker comparison circuit 15 (S3). Here, when the head marker data read from the EEPROM 13 and the head marker data set in the head marker comparison circuit 15 match, the process proceeds to the next process.
[0035]
If they do not match, it is determined as a reading error, and the top marker data is read again. The number of times of rereading is counted (S10), and when the number of times of rereading exceeds a predetermined number of times, for example, 5 times, it is determined that there is some trouble in the EEPROM 13. After setting the initial value of the register circuit 12 in advance in each register (S14), the control microcomputer 11 is activated (S15) and performs normal processing.
[0036]
By performing the processing as described above, even when the data in the EEPROM 13 is not normally read for some reason, each circuit can be set and started with the initial value that the register circuit 13 has in advance. Therefore, the minimum functions necessary for the operation of the video camera can be ensured, and the video camera can be used.
[0037]
If the head marker data match, it is next determined whether or not all the registers have been set (S4). If all the registers have not been set, the setting flag is read from the EEPROM 13 (S5). The setting flag is composed of 8 bits and designates whether or not setting is required for 8 registers.
[0038]
Here, when the bit of the setting flag is 1, setting of the corresponding register is necessary, and when it is 0, setting is not necessary. In addition, register numbers are assigned in ascending order from the LSB (least significant bit) to the MSB (most significant bit) of the setting flag. For example, taking the setting flags of register numbers 0 to 7 as an example, if it is necessary to set the registers of register numbers 2, 3, 5, and 6 among these registers, the setting flag is 6Ch (hexadecimal notation). Become.
[0039]
After reading the setting flag, the bits of the setting flag are checked in order (S6). If the register needs to be set, the setting value is read from the EEPROM 13 (S7), and the setting value is set in the corresponding register of the register circuit 12. (S8). The above operation is repeated until the confirmation of all the bits of the setting flag is completed (S9). Similarly, when there is no need for register setting, the above operation is repeated until all bits of the setting flag have been confirmed. Note that initial values are set as they are for registers that are not required to be set.
[0040]
When the confirmation of all the bits of one setting flag is completed, the next setting flag is read from the EEPROM 13, and the above operation is repeated until the setting of all the registers is completed. When it is confirmed that the setting of all the registers is completed (S4), the end marker data written in the final address of the data in the EEPROM 13 is read (S11). The end marker data is composed of 2 bytes. The end marker comparison circuit 16 compares the read end marker data with the end marker data set in the end marker comparison circuit 16 (S12).
[0041]
When the end marker data read from the EEPROM 13 and the end marker data set in the end marker comparison circuit 16 match, it is determined that the setting of the register circuit 12 has ended normally. Then, the control microcomputer 11 is activated (S15) and normal processing is performed.
[0042]
If the end marker data does not match, it is determined that there is an error in reading the EEPROM 13. Therefore, rereading is performed from reading of the first marker data (S2). The number of times of re-reading is counted (S13), and if it exceeds a predetermined number of times, for example, 5 times, it is determined that the EEPROM 13 has some trouble. In this case, an initial value that the register circuit 12 has in advance is set (S14), the control microcomputer 11 is activated (S15), and normal processing is performed.
[0043]
By performing the processing as described above, when the EEPROM 13 is being read for some reason, when a reading error occurs or normal reading cannot be performed even after re-reading, the initial value that the register circuit 12 has in advance is set. By setting the register, it is possible to ensure the minimum functions necessary for the operation of the video camera.
[0044]
Further, in the case of taking the startup process as described above, if a setting flag reading error occurs, all subsequent register settings are affected. For this reason, it is important to confirm whether reading of the EEPROM 13 is normally completed by the end marker data, and it is possible to improve operation reliability by checking whether the reading is normally set using the marker information.
[0045]
By the way, when the total number of registers is 32, the capacity required for the conventional EEPROM 13 is 32 bytes. However, by storing the setting flag and necessary setting value for each register in the EEPROM 13 as described above, even if the first marker data and the end marker data are included, only 16 bytes are required. Therefore, the capacity of the EEPROM 13 can be halved, and the cost of the memory can be reduced. Further, the reading time and setting time of the EEPROM 13 can be shortened to ½, and the startup time of the video camera can be shortened.
[0046]
Further, when the data of the EEPROM 13 is analyzed by another person, since the setting flag and the setting value are irregularly mixed, it is difficult to analyze the data unless the video camera activation process is known. Therefore, it is possible to prevent leakage of setting contents and outflow of know-how such as video camera adjustment.
[0047]
In addition, since the setting flag and the setting value are mixed in the data of the EEPROM 13, the temporary storage buffer memory required in the EEPROM reading circuit 14 may be about 1 byte for storing the setting flag. It is possible to configure with a program.
[0048]
In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention. The marker information is not limited to two, but may be plural or one.
[0049]
A removable storage medium such as a memory card, a magnetic disk, or an optical disk may be used as the storage means for storing the set value. Each individual has a storage medium and is attached when the imaging apparatus is used. When sharing an imaging device, settings can be made according to each individual.
[0050]
【The invention's effect】
As is apparent from the above description, according to the present invention, when setting is made for the video signal processing circuit at the time of startup, since there is little setting information to be called from the memory, it can be set quickly and the startup time can be shortened. In addition to the setting information, other information is also stored in the memory, so that it becomes difficult to analyze the setting information from the contents of the memory, and security can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a video camera according to an embodiment of the present invention. FIG. 2 is a diagram showing register settings. FIG. 3 is a diagram showing data stored in an EEPROM. Flow chart [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image pick-up element 5 Luminance / color signal creation circuit 6 Gamma correction circuit 7 White balance adjustment circuit 8 Matrix correction circuit 9 Luminance / color signal synthesis circuit 11 Control microcomputer 12 Register circuit 13 EEPROM
14 EEPROM read circuit 15 Start marker comparison circuit 16 End marker comparison circuit

Claims (6)

A processing means for processing a video signal from the image sensor, a setting means for setting a plurality of internal information necessary for the operation of the processing means at startup, and a storage means for storing the internal information to be set The storage means stores apparatus-specific setting information necessary at the time of activation among the internal information, and also stores identification information indicating necessity of setting at the time of activation for each internal information. . In the storage unit, according to claim 1, setting information which is an internal information and settings needed to correspond to a certain number of the identification information and the identification information, characterized in that it is stored so as to correspond to all the internal information The imaging device described. Comprising a checking means for setting information from the storage means to check whether the set successfully, when unable to set properly, the setting means, according to claim 1 or 2, wherein the setting the initial information in advance held Imaging device. The marker information is stored in a specific area among the areas in which the setting information is stored in the storage means, and the check means determines whether or not the marker information has been normally set by checking the marker information. 3. The imaging device according to 3 . The imaging apparatus according to claim 4 , wherein the marker information is added to at least one of the head area and the end area. Configuration information to any one of claims 1 to 5, the adjustment value for suppressing the device-specific variations in production, or setting means is characterized in that it is different from the set value from the initial value in advance held The imaging device described.

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